You hit up the maintainer and negotiate a deal for that?

If all you’ve got is relative pocket change they probably aren’t going to agree but if you put real money behind it and it doesn’t go against their vision of the project then most people would be willing to accept actual contracting work to expand their project.

Sounds like a lot of trouble to go through, vs just sending some funds to a wallet with the assurance it'll go where you want it to or return to you.