An experienced Unity 3D developer is needed to add Firebase authentication feature into the existing App

Need an experienced Unity 3D developer who can add firebase authentication functionality into the existing GPS based 3D tourist application.

Environemnt: Unity 2019.4.32f1
Target build platforms: Android, iOS

After this task done, I have more tasks here and there. So only experienced and skilled Unity 3D developer is needed who I can work with afterward.