Hi casuarinas,
welcome to the Apple (user-to-user) Community.
Re: My apple ID is from the US, and I am currently in Italy. I bought the AirPods Pro 2 in Germany.
Some Hearing Health features are not currently available in every region.
See: Countries or regions where the Hearing Aid feature is available
(NB: three separate feature lists) AirPods Pro 2 - Hearing Health Feature Availability - Apple
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Re: AirPods Pro 2 not showing Hearing Assistance function
Apple Support's online video may be helpful:
https://www.youtube.com/watch?v=Q5noO6dnGBs
Apple Support also provides helpful "how-to" articles:
Use the Hearing Aid feature on your AirPods Pro 2 - Apple Support
Take a Hearing Test with AirPods Pro 2 - Apple Support
This feature is only available in the United States and Canada.
Use Hearing Protection with your AirPods Pro 2 - Apple Support
Apple's Hearing health website: AirPods Pro 2 - Hearing Health - Apple
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Other info. if needed: Seems Apple's "Headphone Accommodations" works with AirPods Pro:
Customize headphone audio levels on your iPhone or iPad - Apple Support
Overview: Apple's Accessibility features for hearing on iPhone - Apple Support
For Apple phone numbers around the world:
See: Contact Apple for support and service - Apple Support
All the best :-)