NF-e Delphi. Reception function

Question

I have no experience in this area of Nfe. I was guided by the support as initial tests using the function:

RecepcionarLoteRpsSincrono(const nfseCabeMsg: WideString; const nfseDadosMsg: WideString): 
  WideString;

My question at the moment is what the Widestring parameter should pass, some example for testing.

Type: nfseCabeMsg := 'Xyz'; nfseDadosMsg := 'abc';

So pass as function parameters. The examples I have are the complete XML but since I must use the function I need to know which passage I pass for each parameter.