Yes you can freeze bananas with the skin or banana peels still on the banana.
However if you do freeze the banana with the skin or banana peels on it will be somewhat difficult to remove the banana peel from the frozen banana when you're ready to eat or use the frozen banana.
When you freeze bananas with the banana peels on the banana peels turn dark and get soft which makes the banana peel harder to remove.
The banana is still safe to eat when the banana peel does turn dark and gets soft but it just makes it harder to remove the peel from the banana.
So it's best to remove the banana peel or banana skin before you freeze them.
I recommend cutting up the banana or at least remove the peel from the banana and then place them in airtight containers or Ziploc bags before freezing the bananas.