To sende PEPPOL document as a Invoice the VAt Scheme code must be in the countries / regions in BC, in the new way as numbers...
If dont have those in BC you can look it in the below link
If they are not correct you get this error
Electronic Address Identifier Scheme
"message":"Invalid Document","errors":[{"context":"/Invoice[1]/AccountingSupplierParty[1]/Party[1]/EndpointID[1]","pattern":"","text":"[PEPPOL-EN16931-CL008] Electronic address identifier scheme must be from the codelist "Electronic Address Identifier Scheme "","isWarning":false},