Facebook sign in plugin not working

I’ve double-checked my api keys and secret keys and they’re definitely synced up to my Facebook developer account.

Everything seems to be in order -

The app domain also seems to be correct. I’ve also tried Log in but I still get the following error on mobile view -

And the following error on desktop view -

The UI has been changed quite a bit since this video came out -

So it’s quite difficult to figure out what’s going wrong here.