CORS Error while calling Appian Web API from an external application

Hi,

I am trying to call my appian web api from my angular application which is on localhost however it is throwing cors error.

NOTE: I tried with Postman it is working fine (Getting expected response).

Error i am getting : Appian api end point from origin 'http://localhost:4200' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Thank you in advance.