iPhone MagSafe magnets

Hello. I have always gotten a MagBak case for my iPhones (link here)- https://magbak.com/products/magbak-for-iphone-11-pro-max

That case has magnets in the case. It allows me to stick my phone to anything metal (fridge, gym equipment, etc.)

so my question is- Do the new iPhone 12s have magnets inside that will allow the phone to attach to anything metal like a fridge?

Or are the magnets in the accessories? Then if magnets are in the accessories like cases, will the phone stick to a metal surface when in that case?

thanks much