plugin that allows user to make payments

Hello everyone and thanks for accepting me.
I am currently searching some kind of plugin that allows user to make payments of an specific amount monthly (like a subscription but of an amount that they can set up through an input ) this is for receive payments of credits and they should be able to discount of an total amount. I found one woocomerce subscription and another of membership but not quite what I need since they have to be able to set the amount to pay.
Thanks in advance