

It’s free to test, and nobody’s obligated to anything, it’s entirely down to people who actually want to. Beta testers get the full app and all the Pro features for free, during the beta and after as a thank you. That’s just how beta testing works, people who run this stack and are curious get early access and help shape it, and they get the paid product for nothing in return.
Calling that a job advert is a stretch. It’s an optional beta with a free product attached, not unpaid labour. If it’s not for you, no worries, just scroll past
My friend, the tester keeps the app afterwards
If the tester doesn’t agree with it, then by all means, don’t become a tester :D