This Apple account is invalid or unsupported.
I left the iCloud account to run it on the other iPhone, but it happened like you read (This Apple account is invalid or unsupported) please help me
iPhone 11, iOS 26
Did you try the steps mentioned in this related article?
If your Apple Account is locked, not active, or disabled - Apple Support
If you have proof of purchase, Apple might be able to help:
Additional Support - Activation Lock