There sure is a good number of HK donation websites popping up here and there since the fiasco, but I'm personally more comfortable in donating through the Human Rights Foundation. Idunno, I'm more comfortable donating through them as I feel like it's more guaranteed that my money is going somewhere.
Also, their CSO, Alex Gladstein, is an avid bitcoiner!
https://hrf.org/programs_posts/hong-kong-desk/https://hrf.org/donate-bitcoin/You can also volunteer for a pro-Hong Kong organization. We just started doing it, really... some Hong Kong Canadians asked for help protecting their website, and we said "OK." They've already been getting DDoS'd ever since they testified to Canadian parliament. We had existing connections in the ESL/immigrant community, but you can find people in need of help if you look around at their rallies and stuff.