So I recently installed iOS 15 of the beta now in the official release comes can I just updated or do I have to delete everything and restart again?

now in the official release comes can I just updated or do I have to delete everything and restart again? I’m new at this. Thanks.

So I recently installed iOS 15 of the beta now in the official release comes can I just updated or do I have to delete everything and restart again?
 
 
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