Venmo is only available in the US.
Cash App is only available in the US and the UK.
Consider adding PayPal info (careful not to dox yourself!), stating what gift cards you would accept (most of the time it's possible for someone outside the US to buy a digital gift card through a US website and provide the code to you) or if you are a more frequent flyer perhaps consider LiberaPay or a similar donation/crowdsource platform (N.B. I don't use LiberaPay, I haven't heard anything good or bad about it, though it appears to be fee free but you should still do your due diligence and check the conditions like minimum payout amounts and how frequently you can cash out etc. Don't take my mention as an endorsement or anything beyond a suggestion).
If you take these steps then you're going to make more opportunities for people outside the US to donate to you.
(A follow up suggestion to the mods: requesting gift cards may open the door to struggle sessions regarding boycotts and poverty-shaming.
Might be worth adding a rule prohibiting people from grilling people over these matters; if someone cannot buy an Amazon gift card for someone else due to matters of conscience that's perfectly reasonable but it's not cool to chastise a person who is experiencing financial hardship and/or major access barriers over opting for Amazon gift cards for those reasons. Boycotts are often a luxury to people who are experiencing desperate circumstances.)
Crypto is indeed useful for one thing and one thing only, and that is evading authorities. That's what it's been used for since its inception, buying drugs and other illegal shit.
Crypto seems like it's marketed as being anonymous but it's really just de-identified as far as I'm concerned.
Look I'm no expert in this so I haven't investigated it to any significant amount of detail but the blockchain is a really good way to permanently record your every transaction, and that is something that concerns me.
Crypto does allow for the free flow of currency in a way that is otherwise tightly restricted but I really don't feel nearly as confident in crypto being as anonymous as it gets made out to be.
If you've ever worked with data or stuff like survey methodology, de-identified data is vastly different from anonymous data. Imagine you work in a company and you're the only practicing Jewish person, with the rest being Christian or atheist. If an anonymous survey went out at your workplace, it doesn't matter how many preventative measures are put in place because there are going to be certain identifiers that can distinguish you from all other respondents. As soon as a profile has been established that only one person can meet, the data is still de-identified but you are no longer anonymous. And this is without involving things like network analysis - it's possible to identify people based purely on those who they interact with, although this is very context-dependent and complex but think about how certain serial killers have been identified by enough people who are related to the serial killer in some degree filling in enough gaps that the candidate is narrowed down to just one person. Obviously this is an analogy but I'm you get what I'm driving at here.