What's user credentials need to provide Google console verification app

I am creating one app where provide only two way log in system one is continue with Google and another continue with Facebook and if I published this app in Play Store then what’s credentials need to provide Google.

Because here not available any user id and password.

If I send app for review without user credential then any chance of rejection or need email id and password provided ?

The application must already have a registered user who can log in, for example. [email protected]
those credentials load into the google console

I didn’t Understand this process .

I upload app where user can log in only using continue with google and facebook . Then how play console review team check my app without log in my app because i am not giving any things in user credentials section

But how I add register test user using Google Authentication and how provide email false because authentication doesn’t proceed