We welcome tips and donations. The first option is to add a tip to your order during checkout. The tip can be any amount you want.
If you want to simply send a donation without purchasing anything you can purchase a gift card and mention in order notes that you don't want to use it.
PS: Preferably you can us tip and send donations by bitcoin network or through the lightning network - a protocol that enables faster and cheaper bitcoin transactions. The BTCPay server is hosted on our own server.