Doesn't look like it will be possible. That's a deal breaker for me, I don't need another app spying on me on my phone.
https://www.ryanair.com/gb/en/lp/explore/digital-boarding-pa...
If a company is going to make something a requirement like this, they need to also invest in the effort to support everyone's device, and not block people with old, icky phones.
Selling my location, list of the installed apps, cookies, whatever they can extract.
That's for starters.
But most importantly why the hell should I be forced to use phone app if having a printed pass was good enough?
I need to reverse your surprising question into: should I be expected to install, update, maintain and use apps of ALL the service providers I use?
Separate app for train provider A, another for train provider B, another for bus provider C.
No paper tickets.
An app to purchase groceries, another app to pay for the parking, another app to buy a coffee, another app to buy a newspaper in the kiosk. And app to check in the hotel, an app to order food in the restaurant, an app to call the tax return website (not the phone, an app).
Can you see now how absurd is to normalise it?