Fork the repository by clicking the button at the top right
Clone the forked repository by using the command git clone forkedrepolink
Open the flutter project in your IDE, run flutter pub get in the terminal or in Android Studio.
If there is an error, go to pubspec.yaml and go to sdk version and downgrade and upgrade according to the error msg shown, also in dependencies change version of every package to "any".
Everytime Before you work, go to your github forked repo and press "sync changes" then go to your project and run git pull in the terminal.