Only one big caveat:
I have no idea how long this will last. Living in a highly regulated country I think it is just a matter of time before they make KYC obligatory... So enjoy while it lasts :)
Bitrefill is a good service indeed. They have been in business for a long time. So let's hope they stay the same as they are now.
I used them in 2019 to buy Hotel.com coupons because there were problems in my country with credit cards and it worked very well.
I feel stupid for only finding out about this now :D
You shouldn't feel stupid. I found it because I had a need. I had to book a hotel, and I didn't have a credit card to pay, nor how to buy coupons with it. At that time Bitrefill was a lifesaver for me. And better be happy of knowing about it now ;)