Getting alot of errors when connecting flutter app to firebase

Launching lib\main.dart on TECNO BD2d in debug mode...
Running Gradle task 'assembleDebug'...

FAILURE: Build failed with an exception.

* Where:
Build file 'C:\Users\Brayan Malova\AndroidStudioProjects\untitled4\android\build.gradle' line: 10

* What went wrong:
A problem occurred evaluating root project 'android'.
> Supplied String module notation 'com.google.gms.google-services 4.4.2' is invalid. Example notations: 'org.gradle:gradle-core:2.2', 'org.mockito:mockito-core:1.9.5:javadoc'.

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 3s
Error: Gradle task assembleDebug failed with exit code 1