from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. code example

Example 1: origin 'http://localhost:4200' has been blocked by CORS policy

'Content-Type': 'application/json',
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Headers': 'Content-Type',
      'Access-Control-Allow-Methods': 'GET,POST,OPTIONS,DELETE,PUT',
      'Authorization': 'Bearer key',

Example 2: ccess to XMLHttpRequest at 'http://127.0.0.1:5000/ has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

@app.route('your route', methods=['GET'])
def yourMethod(params):
    response = flask.jsonify({'some': 'data'})
    response.headers.add('Access-Control-Allow-Origin', '*')
    return response