I tried creating a file named redirect.js, pasted the lines you wrote, copied the url and pasted it in chrome and got this:
https://api.backendless.com/AF8A6FD1-7119-6D55-FF83-BC9AA0072B00/v1/files/web/scripts/redirect.js
Error: Cannot find module ‘/repo/web/scripts/redirect.js’
the same happened with the default hello.js file in the scripts:
https://api.backendless.com/AF8A6FD1-7119-6D55-FF83-BC9AA0072B00/v1/files/web/scripts/hello.js