postman: You need to enable JavaScript to run this app

I spent some times pondering on this trepidation.. and then suddenly i realized what was going on..

1. the endpoint does not exist, it could be a misspelling
2. not in the same directory as you expect it to be,
   try adding or removing “/” at the beginning of the url, particularly if you don’t specify the hostname, i.e. fetch('getusername') is different from fetch('/getusername') .
   . This acceptable in development but NOT when already deployed, it points to different path.
3. the endpoint may be working fine in the Development,
   but somewhere within in the Production/Staging, it generated some exception.