Can't get a Public Link to test iOS app on TestFlight
It looks like you make need to add some builds to your tester group, so that the public link can be enabled.

Try the following:


Go to your Testers Group (i.e. "Testers &amp; Groups->Público em Geral" in your 2nd screenshot)
Click on the "Builds" tab
Add one of the builds that you’ve uploaded recently
Click back to the "Testers" tab


You should now see an option for "Enable Public Link".

I found this article pretty handy for some step-by-step instructions.