2checkout gateway marketpress

Hi, i have 3 issues:

1.- i need to show you a picture of my configuration, we believe nothing is wrong, however, we have a message:

Parameter Error

A parameter error was encountered when attempting to process this sale.

Please notify the supplier so that this can be resolved as soon as possible.

when we try to buy a product from:


2.- when i click buy it should send me to the checkout process, i dont see a way to configure this, it accept the request but keep in the same page

3.- we will sell subscriptions, 2checkout accept this, does market press does it?

PS: we are experienced developers and love wordpress too, thanks