I’ve got some standing orders of 1 or 2 euros every month for bigger projects like grapheneos and kde. And for small apps that I actively use, I try to donate 5 or 10 euros now and then. It’s not much but I believe if everyone is doing their part we succeed in the long run
Crypto is likely the best solution. You should get some Monero and donate that. You can ask an AI chatbot like Google AI studio how to get some and put it into a self custody wallet in your country.