Pay Pal - non-profit. . type of plan

I have been reading your answers about PayPal and non-profits, but am still unclear: I try to add the PayPal button to my website and it tell s me to upgrade my account. . but it is (to me) totally unclear, what I should upgrade to! (We have the minimal "Starter" Package). I tried looking at "Add ons", but they don't say PayPal.

So, is that my first step? (upgrade). Yes, we already have a PayPal account, etc.