You can use OnCustomResponseEvent.
example of using this event is shown in this code snippet
it can be like:
// ROSOAPMessage should be drop to form
// '/v1/soap' string shouldn't be registered in `ROIndyHTTPServer1.Dispatchers`
procedure TMegaDemoServerMainForm.ROIndyHTTPServer1CustomResponseEvent(const aTransport: IROHTTPTransport;
const aRequestStream, aResponseStream: TStream; const aResponse: IROHTTPResponse; var aHandled: Boolean);
var
op: TROResponseOptions;
begin
if AnsiSameText(aTransport.PathInfo,'/v1/soap') then begin
MainProcessMessage(ROSOAPMessage,atransport,aRequestStream,aResponseStream,op);
aHandled := True;
end;
end;