[BUG] Erlang-server schema validation failure for json string body

Description

Not sure if it's because of my spec, but I'm opening it to get some help.
Starting from the swagger 2 API spec in the below yaml, I run the generator for erlang-server.
THis produces the openapi.json priv file and .erl stuff.
Among my APIs I have a post with a json string body. This API fails with the following info log:

Unable to process request for 'RootPost': {wrong_param,binary,schema,#{error => {schema_not_found,"#/components/schemas/binary"},type => schema_invalid}}

The failure occurs in *_api.erl file around here:

validate_with_schema(Body, Definition, ValidatorState) ->
    jesse_schema_validator:validate_with_state(
        [{<<"$ref">>, Definition}],
        Body,
        ValidatorState
    ).

I took deps from the README.md

    {jesse,  {git, "https://github.com/for-GET/jesse.git", {tag, "1.5.2"}}},
    {jsx,               {git, "https://github.com/talentdeficit/jsx.git", {tag, "2.9.0"}}},
    {cowboy,            {git, "https://github.com/ninenines/cowboy.git", {tag, "2.5.0"}}}

openapi-generator version

4.0.1-SNAPSHOT
not a regration afaik

OpenAPI declaration file content or url

This is the swagger 2 input yaml:

paths:
  /:
    post:
      tags:
        - index
      description: "Create a new Table Index"
      parameters:
      - name: "index"
        in: "body"
        description: "Table Index to create up"
        schema:
          type: "string"
      responses:
        201:
          description: "New Index Created"

This is the openapi3 output json from the cli

"paths" : {
    "/" : {
      "post" : {
        "tags" : [ "index" ],
        "description" : "Create a new Table Index",
        "requestBody" : {
          "description" : "Table Index to create up",
          "content" : {
            "*/*" : {
              "schema" : {
                "type" : "string"
              }
            }
          },
          "required" : false
        },
        "responses" : {
          "201" : {
            "description" : "New Index Created",
            "content" : { }
          }
        },
        "x-codegen-request-body-name" : "index"
      }
    },

Command line used for generation

docker run --rm \
	-v $(pwd):/local \
	openapitools/openapi-generator-cli \
	generate \
	-i /local/priv/swagger.yaml \
	-g erlang-server \
	-o /local/out/

Steps to reproduce

Start application and
curl -X POST "http://localhost:5678/" -H "Content-Type: application/json" -d '"hello"'

Suggest a fix

Possibly there should be no schema (no /components/schemas) to validate at all for a json string (?)

Start by reproducing the issue with the provided swagger.yaml, generator command, and curl request, then inspect the generated *_api.erl around validate_with_schema/3 and compare it with the openapi.json output. Done means a JSON string body no longer produces schema_not_found for components/schemas/binary and the generated erlang-server request validation behaves correctly.