hi, I installed backend and frontend on my vps, and to visit backend it shows:

"it works!"

which i assume it works, and i run frontend and always got:

TypeError: Failed to fetch

i thought this might be something wrong about my backend, so i set the backend point to try-puppeteer.appspot.com in app.js as below:

const BACKEND_HOST = ( 'https://backend-dot-try-puppeteer.appspot.com');

and still i got the same TypeError: Failed to fetch

any idea what i got wrong?

thanks?