Fix subscription validation
diff --git a/api-gateway-config/scripts/lua/management.lua b/api-gateway-config/scripts/lua/management.lua
index 08b9276..076785f 100644
--- a/api-gateway-config/scripts/lua/management.lua
+++ b/api-gateway-config/scripts/lua/management.lua
@@ -225,7 +225,7 @@
   -- Convert json into Lua table
   local decoded
   if next(args) then
-    decoded = convertJSONBody(args)
+    decoded = utils.convertJSONBody(args)
   else
     request.err(400, "Request body required.")
   end