Restore problem with iCloud backup

Hi,

I have an issue that I don't know if it's possible to solve without iTunes..

I had to reset(and erase everything) on my iPad 2 IOS 9.3.5.

During the initial setup I entered my iCloud password incorrectly and locked my account. I got a family member to login on a PC and reset. However now, at the final step of the initial setup, when I reach the restore an iCloud backup it says the password is wrong

I'm guessing this is because my Apple ID password is now different to the password when I backed up.

Can the backup's password be updated by apple support or do I need a device with iTunes?

Can I even restore the backup with iTunes?

Thanks,

J