Currently, within CurseForge projects, the author has the option to set up a donation type. The author can choose from PayPal, PayPal hosted or Pledgie. The end result is a button on the project's page allowing visitors to donate to that particular project.
Issues arise from this when a project is not necessarily owned by a single individual or in my case, my PayPal email address isn't something I want people to know.
Nowadays its a lot more common to see content creators use sites such as Patreon to accept donations from their communities. So, an option to specify a Patreon link would be a great addition and fairly straightforward to implement.
Furthermore, this functionality could be extended to allow users to specify other platforms or a custom URL entirely (ensuring that the external link URL warning is displayed for custom URLs).