Some options I know of are Liberapay [0], OpenCollective [1], and GitHub Sponsors [2]. Best way would probably be to view each FOSS project’s page and see which they accept. A little tedious but you can set a recurring donation and forget about it. There’s also sometimes an option to discover projects you can donate to like on OpenCollective.

[0] https://liberapay.com/

[1] https://opencollective.com/

[2] https://github.com/sponsors