You can make a donation to the Buddhist Institute here via the non-profit organization betterplace.org.
After entering your data and clicking on "continue", you can additionally make a voluntary donation to betterplace.org. The contribution for the additional donation will be pre-filled depending on the amount of your donation to the Buddhist Institute. This additional donation will support the operation of the non-profit organization betterplace.org.
If you like, you can change this voluntary donation to betterplace.org on the next page after clicking on "Change contribution for betterplace".