Add Flex API into KPI models

models/intermediate/kpis/int_kpis__metric_daily_invoiced_revenue.sql

@@ -188,6 +188,13 @@ select
             else 0
         end
     ) as xero_screen_and_protect_net_fees_in_gbp,
+    sum(
+        case
+            when ixsdm.accounting_root_aggregation = 'Flex API'
+            then ixsdm.line_amount_wo_taxes_in_gbp
+            else 0
+        end
+    ) as xero_flex_api_net_fees_in_gbp,
     sum(
         case
             when ixsdm.accounting_root_aggregation = 'Guesty Resolutions'