AS3 JSON Schema Validation not working

Hi - First Devcentral from me question coming up !

 

I'm trying to add the schema for AS3 to validate my declarations but it doesn't seem to do anything. I have followed the guide below and tried creating a new json file but still nothing. I can access the link from the file in visual studio code

 

https://clouddocs.f5.com/products/extensions/f5-appsvcs-extension/latest/userguide/validate.html

 

Any ideas on how to get this working?

 

Thanks in advance