Among the github files attach a pdf as a mini documentation.
to run the application it is necessary to enter the google API console.
to enter the console you can enter the following link:
https://console.developers.google.com/apis
Then go to credentials, and edit the credential that has the name OAuth 2.0 Client IDs.
there you will find two spaces where you enter the url of the domain where you want to run it.
If you want to run the application on a local server you must enter the url of said server example: "localhost", "127.0.0.1", "localhost: port" atc.
if the error is displayed: idpiframe_initialization_failed, clear the history of the browser that is being used. This is because the browser has a bad or obsolete cookie from the application.