Epicor REST help

If that is all done then how would you get the data out of responsedata since it returns a string? You would have to convert it no? I am trying to do something like this to add all the po lines:

dynamic searchPOS = EpicorRest.BoPost("Erp.BO.PORelSearchSvc", "GetRowsExcludeGlobal", new { whereClausePoRel = $"PONum = {po}", excludeGlobal = true, pageSize = 100, morePages = false, absolutePage = 0 }); ;

                    if (searchPOS.IsErrorResponse)
                    {
                        print(searchPOS.ResponseError);
                    }
                    else
                    {
                        var polines = searchPOS.ResponseData;
                        foreach(var result in polines)
                        {
                            var GetDtlPOLineInfo = EpicorRest.BoPost("Erp.BO.ReceiptSvc", "GetDtlPOLineInfo", new { vendorNum = vendor, purPoint = "", packSlip = ps, packLine = result.poLine, serialWarning = "" });

                        }
                    }