[REQ] Help with the "frontend part"

I am part of a team in this moment.
Normally I work on frontend, but it happened there is no other who can do the Typescript part either than me.
I was given the task to build the client and the APIs.
I tried with your documentation and bought and read the book 'A Beginner's Guide to Code Generation for REST APIs (OpenAPI Generator).pdf', but unsuccessfully.
A colleague of mine did the C++part executing:
/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -jar /home/.../openapitools/openapi-generator-cli/5.0.0-beta2/openapi-generator-cli-5.0.0-beta2.jar generate -i ./petstore.yaml -g cpp-restbed-server -o ./api

and obtained this folders:
find api/
api/
api/.gitignore
api/.openapi-generator-ignore
api/git_push.sh
api/api
api/api/UserApi.h
api/api/PetApi.h
api/api/StoreApi.cpp
api/api/PetApi.cpp
api/api/StoreApi.h
api/api/UserApi.cpp
api/README.md
api/.openapi-generator
api/.openapi-generator/FILES
api/.openapi-generator/VERSION
api/model
api/model/Category.cpp
api/model/ApiResponse.cpp
api/model/Pet.h
api/model/ApiResponse.h
api/model/Category.h
api/model/Order.h
api/model/Tag.h
api/model/User.h
api/model/Tag.cpp
api/model/Order.cpp
api/model/Pet.cpp
api/model/User.cpp

What should I do to continue the task with my part in Typescript?
What are the istructions to generate the remaining code to request APIs?
I didn't understand from the book.
I am working on a Linux machine.
Let me know, please.

logs for the C++ part:
/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -jar /home/../.m2/repository/org/openapitools/openapi-generator-cli/5.0.0-beta2/openapi-generator-cli-5.0.0-beta2.jar generate -i ./petstore.yaml -g cpp-restbed-server -o ./api
[main] INFO o.o.codegen.DefaultGenerator - Generating with dryRun=false
[main] INFO o.o.codegen.DefaultGenerator - OpenAPI Generator: cpp-restbed-server (server)
[main] INFO o.o.codegen.DefaultGenerator - Generator 'cpp-restbed-server' is considered stable.
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/json)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/json)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] INFO o.o.c.languages.AbstractCppCodegen - Environment variable CPP_POST_PROCESS_FILE not defined so the C++ code may not be properly formatted. To define it, try 'export CPP_POST_PROCESS_FILE="/usr/local/bin/clang-format -i"' (Linux/Mac)
[main] INFO o.o.c.languages.AbstractCppCodegen - NOTE: To enable file post-processing, 'enablePostProcessFile' must be set to true (--enable-post-process-file for CLI).
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/ApiResponse.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/ApiResponse.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Category.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Category.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Order.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Order.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Pet.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Pet.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Tag.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/Tag.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/User.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/model/User.cpp
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/json)
[main] WARN o.o.codegen.DefaultCodegen - Multiple MediaTypes found, using only the first one
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/json)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] WARN o.o.codegen.utils.ModelUtils - Multiple schemas found in the OAS 'content' section, returning only the first one (application/xml)
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/PetApi.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/PetApi.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/StoreApi.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/StoreApi.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/UserApi.cpp
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/api/UserApi.h
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/.gitignore
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/git_push.sh
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/README.md
[main] INFO o.o.codegen.TemplateManager - Skipped /home/atlas/sources/test/./api/.openapi-generator-ignore (Skipped by supportingFiles options supplied by user.)
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/.openapi-generator/VERSION
[main] INFO o.o.codegen.TemplateManager - writing file /home/atlas/sources/test/./api/.openapi-generator/FILES

Start with the issue's ./petstore.yaml input, the Java CLI command, and the generated api/ directory; the payload names no repository source file or test. Reproduce the reported generation context and determine which TypeScript client target and options are intended. Done would be clear, project-specific instructions for generating and using the requested TypeScript API client.