As requested by a number of Coinbase users, we just launched a new feature where people can set their own donation amounts.
When you go create a payment button there is a new ‘advanced options’ section.
You can also suggest some amounts for the user when generating the button.
And it will look like this:
And of course, it works with other currencies, regular payment buttons (not just donations), hosted checkout pages, and more.
You can try creating one of these new donate buttons here (signin required). Hope it helps!