Don’t know if this is a naive question but could you re assign the iPad to an available region in settings e.g from UK to Ireland? where it is available.
That won’t work but the following will help you to set them up.
I set a new pair of AirPod Pro 2s up for my big sister today in the UK and she is really happy with them. She cannot believe that she can hear music properly again.
Annoyingly she had her update settings on automatic on her iPhone so it was on IOS 18.1 so I just set them up on her iPad mini that is on IOS 16.
If you have another Apple device that is running an older IOS you can set them up with no restrictions. An iPhone 12 is new enough.
Pair the AirPods and stick them in your ears and do a Ear tip test to make sure you have a good seal and download the Mimi hearing test app and take a hearing test.
You access the options via Headphone Accommodations in Settings/Accessibility/Audio Visual and you can load your audiogram onto the AirPods or take a hearing test using the Mimi app from the app store.
If you want to use your own existing audiogram you can. There are many videos online that will help you.
I have been using them since September but people have been using the AirPod Pros as hearing aids since 2020 and September 2022 for the AirPod Pro 2s when they were first launched.
Check out this article if you are skeptical.
https://www.hearingaidknow.com/hearing-aid-functionality-introduced-to-apple-airpods-pro
The menus were simplified and streamlined for 18.1 and the geographical lock has been implemented by Apple as it was one of the requirements of the FDA in the USA.
Other countries like Canada, the UK, France, Spain, India and Italy need to be approved to use them in those countries before the lock is removed.
Setting them up with an older device will allow you use them now. My iPhone is on 17.7.1 and they work very well for my mild to moderate hearing loss.