Here’s the link to United24, the official Ukrainian government donation site (endorsed by Zelenskyy). You can specify that your donation is for humanitarian aid, rebuilding, or military aid. Apple Pay works, and Paypal is fee-free for non-miltary donations.
This is a SDMB thread on donating to Ukraine.
This is a link to Reddit r/ukraine, which has a list of approved charities.
The United24 site includes breakdowns of how much money is being donated each day, and what items are being purchased. A lot of helmets, shoes, underwear, and drones.
Military donations seem to be running about $200,000 per day, which is down, maybe 30%, from a few months back. And while foreign governments are chipping in billions in equipment, anyone who has worked for a charity knows how important non-earmarked funding is. Receiving ammunition is wonderful, but it’s nice to have money to buy toothpaste.