donation button

[Bakenia]

I rent a guesthouse. I want customers to make payments via a Paypal button.

They have to enter the amount themselves.

The only button that does the job is the DONATION button.

Only the term DONATION is misleading.

I already replaced the DONATION button by a customized button.

See http://labakenia.com/en/bank.html

However if you press the button, Paypal uses the verb DONATION everywhere in payment procedure.

Is there a way to change the verb DONATION by PAYMENT or so?