The error "No 'Access-Control-Allow-Origin' header is present on the requested resource" occurs because the server you are trying to access does not allow cross-origin requests from your domain. This is due to CORS (Cross-Origin Resource Sharing) restrictions.

How to Fix It?

1. Server-Side Fix

Modify the server to include the Access-Control-Allow-Origin header in the response:

• Allow all origins (not recommended for production):

  Access-Control-Allow-Origin: *
  

• Allow specific origin:

  Access-Control-Allow-Origin: https://your-allowed-domain.com
  

• In the case of preflight requests, also include:

  Access-Control-Allow-Methods: GET, POST, OPTIONS
  Access-Control-Allow-Headers: Content-Type