Since your files are hosted on another server, a browser will block your requests to them. You need to add the appropriate headers on your files so they can be accessed from your webpage. Review the second post on this thread: No 'Access-Control-Allow-Origin' header
And more resources on CORS here: Cross-Origin Resource Sharing (CORS) - HTTP | MDN
How you set the headers will depend on your hosting server. Fixing the CORS issue will allow the JSON file to load, but you may experience followup issues, so be sure to check the console to see what else you have to fix.