Website Payments Pro on multiple sites?

[toothpick]

I have several websites using Website Payments Pro that I initially gonfigured with the signature option instead of the certificate file option.

Now I am trying to setup my first ProStore... It will not take the signature and wants a certificate file. But I cannot download a certificate file for the WPP API because its already set to Signature for my other stores.... So how can I add the option of a certificate also so ProStores can work?

[toothpick]

Actually I would be happy if I could just get PayPal Express to work with the ProStore. Once it is working, WPP should be easy. It's PayPal Express that is not letting me get a certificate, only a signature.