A donation isn't  "paying" for something. It's a "just because" type thing that you give as a thank you.  It's not a mandatory thing. Think of it like giving someone who you appreciate here, a gift certificate as a thank you for their help or their kindness and generosity. It's just a gift, not payment.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi