magento2-paymentfee

Magento 2 Payment Fee by MagePrince allows store admins to add extra fees for specific payment methods during checkout, giving more control over payment-related charges. Maintained by mageprince on GitHub, where it has earned 40 stars from the community.

It's actively developed around extrafee, free-extension, free-module, and is a solid reference for anyone building with these tools.