How to active iphone after update if we forget our apple id or password

Marking your own post as Solved may prevent others from trying to help because they think you have fixed your problem.

See if you can recover the ID/password. Use every email address you can think of.

Apple ID - How to find your Apple  -  An iCloud e-mail address is an Apple ID.

Apple ID - Find  -       

If you forgot the Apple ID (iCloud) password, enter the Apple (iCloud) ID, and click Forgot Password. See if you can get a Rescue or Notification email option if necessary. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage  -     

Apple ID – Forgot Password  *      

How can activate my i ohone if my apple id password is forgot

See the forgot password information I posted above.