Congratulations on the launch, sounds good!
To differentiate and offer more value than the developer just linking donation link to Paypal or Patreon; I would suggest actively conducting business development for listed open-source project i.e. Marketing a open-source tool as an alternate to expensive, closed tool; offering support for the open-source tool for business etc. and of-course making reasonable markup for the same and passing the bulk to the developer(s).
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