Two thoughts on things that can help:
- For the convenience of bypassing passcode entry and unlocking with Optic ID, your friend can turn on Nearby iPhone Enables Optic ID. If you're signed in to your iPhone with iOS 17.1 or later and Apple Vision Pro with the same Apple ID, you can use your iPhone to turn on Optic ID when you turn on or restart your Vision Pro. You can use this feature if your iPhone is nearby and has been unlocked in the past hour. To turn it on, go to Settings > Optic ID & Passcode, and select your iPhone below Nearby iPhone Enables Optic ID. Read more at How to set up Optic ID - Apple Support.
- For those times where Nearby iPhone Enables Optic ID doesn't work as expected, your friend can enable VoiceOver. VoiceOver gives audible descriptions of what’s in your view—from battery level, to who’s calling, to which apps are open. They can use that to enter their passcode when needed. See Turn on and practice VoiceOver on Apple Vision Pro - Apple Support. Since it sounds like your friend might not need VoiceOver all the time to operate Apple Vision Pro, they can use an accessibility shortcut (e.g. triple clicking the Digital Crown) to quickly turn VoiceOver on or off. See Use accessibility shortcuts on Apple Vision Pro - Apple Support.
Hope this helps your friend enjoy Apple Vision Pro! Let us know how it goes and have a great day!
Edit: If they're just looking to set up Optic ID in the first place, they can enable VoiceOver to enter their passcode before setting it up, and use Nearby iPhone Enables Optic ID and VoiceOver for future unlocks.