How can I get more storage I bought 2t still not enough

You can only buy iCloud Storage which has no relation to , nor does it affect in any way your iPhone’s internal storage capacity.

The local capacity cannot be changed on an iPhone. If it is full, you will need to delete content from the iPhone itself.

iCloud storage is independent of iPhone storage. You can’t increase the storage space on your phone. If you need more space, you will need to delete something.