Hi eagle2012
welcome to the Apple (user-to-user) Community.
Re: Two-factor Authentication When Repair Is Needed
There is a method that may be useful in that scenario:
If you could find the iPhone's serial number (eg: from a receipt, the packaging, eMail)
Find the serial number or IMEI on your iPhone, iPad, or iPod touch
you could enter the serial number online and follow the instructions provided there.
Check Your Service and Support Coverage - Apple Support
You may need to provide proof of purchase at some point.
Am unsure whether two-factor authentication would be requested.
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Else:
You can generally get hands-on Hardware Support by visiting an Apple Store
A reservation is recommended (take personal ID and proof of purchase):
Genius Bar Reservation and Apple Support Options - Apple
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or
One stop for technical support, Apple hardware service, and software support.
Call Apple Support at 1-800-APLCARE (or use the app)
AppleCare Products - Apple
If others in the community have experience with these avenues, they may share.
All the best :-)