Issue with sending message using API InvoiceRequest_Out from S4

Hello,

I am working on a scenario:

S4 Cloud -> SCP -> EDI

EDI message is 810 (Invoice). I configured API "InvoiceRequest_Out" from S4 -> SCP (I hope this is the correct one!). Please can someone help me on following points:

1. when should be the channel in output ? Only suitable option is EDI. Id this correct?

2. when I create an output for EDI, it errors. I tried adding XML in BRF+ (output determination) but XML does not show up in invoice's output options.

Thanks in advance!