If you mean "how do I monetize to keep services afloat", open donation channels, like Patreon, Ko-fi, direct donations like the American Zelle or the Brazilian Pix, referral links explicitly identified as such, etc., and be transparent about finances and that if someone likes the service, their support helps maintaining it.
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If you mean "how do I get users to help pay for the services", open donation channels, like Patreon, Ko-fi, direct donations like the American Zelle or the Brazilian Pix, etc., and be transparent about finances and how, if someone likes the service, their support would be appreciated.