Problem with Firebase on IOS

Hello friends.

I am trying to connect my app with Firebase.
I have tried two completely different applications and the problem is the same:

Only in IOS version does not access the variables of firebase, however in Android there is no problem.

In Firebase I have created a new WEB project as indicated in the official tutorial. I have seen that there is the possibility of Android and IOS, may that be the problem?

help! thanks to everyone

Hi. I still have this problem. Somebody could help me? Thank you.