II have not worked with this package yet, but there are a few things going on with your code that you can explore to start.
In the frontend code…the backend function import should have braces like below. See importing web modules for more information
import { getDriveFolder } from'backend/googledrives';
In your backend file you have a function that is async, but you never use await. Here is some reading on promises.
Finally, another potential issue here is that nothing is being returned from your backend function.
Also web modules always return a promise which you will need to handle in the frontend code when you call it, see the first link about working with web modules for some simple examples.