I need a php Auth SSO Integration for my Flutter App

I'm seeking a skilled PHP developer to integrate Single Sign-On (SSO) into my pre-existing Flutter application.
Key Specifications:

- Implement Single Sign-On (SSO) into existing Flutter application on the php website's backend

Ideal Skills and Experience:

- Strong proficiency with PHP
- Prepared to work with a pre-existing Flutter Application
- Previous experience integrating Google SSO into mobile applications.