Patreon and ko-fi are good alternatives if you don't want a grand Kickstarter campaign.
iirc both platforms have monthly as well as one-time payment tiers, you can also set up shop to sell some predetermined items like extra goodies and stuff.
Since you're probably busy, it's best to not promise any monthly content and go with the one-time option.
edit, there's also buymeacoffee which works the same way, allowing you to earn some tips.