If it's non-flexible, it's probably mentioned, otherwise it isn't, I guess.

I have a holiday booking for June (Rio de Janeiro) with a non-refundable room. In the overview of the confirmation mail of my booking, in the hotel section, it mentions "Non-changeable/Non-refundable" in the room description although I do wonder if this still applies since most hotels offer flexibility given the corona-situation, even on non-refundable bookings. Anyway, I'll see if I make it, and if not, how much money I will get back as a voucher or cash.