Hi is it possible to upgrade my iPhone storage I have 200GB In my cloud storage but my iPhone storage is full 63.4 GB/64GB

iCloud storage is independent of iPhone storage. The only way to increase iPhone storage is to buy a phone with more storage.

Upgrading an iPhone’s storage is not possible.

Clear out your current storage use and/or purchase a new iPhone with more storage. You always require an absolute minimum of 10% of the iPhone’s storage free.