Firebase App Authentication Implementation

Job ID: 37557219

Budget: $30 – $250 USD

For my current already running Firebase application, I'm looking to ensure secure access in it (this app is just a single main page). What I primarily need is:

User Authorization: I'd like an email and password secure login system set up. So only authorized users can have access on that app (single main page)

I am wondering if that's possible in Firebase (for example to embed PHP script in its server, or for example any other way that I can't imagine/don't know)

Please!!! only freelancers with experience in Firebase, authentication, PHP, etc. No more than 3 days deadline.

PS: For your convenience, I have already made an HTML authentication page as well, so finally you don't need to write neither the main page nor the authentication page.