Unable to activate or Find iCloud mail

Recently bought an iphone 15, but I couldn’t find iCloud mail in Settings >apple id>iCloud. Or even if i open up the mail app & try to add iCloud mail, in the main login page it shows jn the below that “iCloud mail is not activated in this device” . If i try to login in the mail app it just keep showing me signing in but it never finish! So anyone knows how can i find & activate icloud mail to use it?

PS. i have tried logging out from my apple id & login in again. nothing happened.