Pre requisites

Prerequisites
Google Drive API enabled
JSON file with credentials

Enable Google Drive API:
Go to the Google Developer Console.
Create a new project or select an existing one.
In the left pane, click "Library."
Search for "Google Drive API" in the list of available APIs.
Click "Google Drive API".
Click "enable" to enable the API for your project.

Create API credentials:
Set up the OAuth consent screen:

In the navigation menu, go to APIs & Services > OAuth consent screen.
Configure the consent screen, making sure to add the necessary scope for Google Drive.
Create credentials:

Go to APIs & Services > Credentials.
Click on "Create Credentials" and select "OAuth 2.0 Client IDs".
Set the application type ("Desktop app") and download the credentials JSON file.

Generate token for the plugin:
Run the plugin manually with the mandatory parameters specified in section "parameters" (example in section "manual execution", in a GUI environment, to generate a token.json file. 
The browser will open and we will be asked to log in with a google account.
The generated token.json should be located in the same directory where the PandoraFMS plugin is configured. Next to the creds.json.
It is necessary to run in a GUI environment to authenticate for the first time and generate a token.