Hello! As per the readme for the package, this code is meant to be run in a backend file. This will not work from your page code, hence your current “is not a function” error.
What error did you receive when testing in the backend?
Also, it appears you have pasted private information from the secrets manage in your screenshot. If this token is not meant to be public, please delete it to protect yourself.
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.