Solution Code not working

Tell us what’s happening:
When I paste my solution code I am constantly getting the answer wrong even though my solution code meets all requirements. I checked the console for the exercise, and it seems that the ‘Access-Control-Allow-Origin’ header has not been set – which may or may not be the root to the problem. If anyone can aid in helping me fix this error, it would be much appreciated.

Your code so far

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36.

Challenge: undefined

Link to the challenge:
https://www.freecodecamp.org/learn/information-security-and-quality-assurance/advanced-node-and-express/communicate-by-emitting

You will need to post a link to the code you are using for us to help you.