how to set CORS allow?

[KrishnaPG]

While trying to access the juttle-engine service (hosted on Azure Linux VM) from browser (localhost) juttle-viewer, encountering:

Fetch API cannot load http://xyz.westus.cloudapp.azure.com/api/v0/directory?path=/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:1337' is therefore not allowed access. The response had HTTP status code 404. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

How to resolve this situation?

• how to set CORS allow header on the server side (juttle-engine service)?
• else anything can be done on the client (juttle-viewer express app) side?