PAC Integration with Digital Receipts Service (CSF Mexico)

Hello folks I'm trying to setup the Mexico Country Specific Funcionality the Installation Guide states that Epicor is currently supporting two PACs, Interfactura and Buzon Fiscal. Buzon Fiscal is handled through a solution developed by Ventus Technologies

But I'll be working with a different PAC

do you have any clue about how to build a compatible webservice to exchange CFDI documents?