Create service account for the project
Select a project. You can create a new one too if you do not have one yet (e.g. jogetsample).
Click on Create Service Account.
Name the service account (e.g. jogetsample).
Remember to check Furnish a new private key and also Enable Google Apps Domain-wide Delegation. Press Create.
A .json file will be downloaded. Open up the file in your favorite text editor.
Enable Google Drive API for the project
Make sure that your current project is selected (e.g. jogetsample).
Click on Google Drive API.
Delegate Google Drive access to the project service account
From the downloaded JSON file earlier, copy the "client_id" and put into the Client Name field.
In the field
Configure Joget Workflow App
From the downloaded JSON file earlier, copy the "client_email" and "private_key" values.
In your Joget app, select Google API Configuration in Properties & Export -> Set Default Plugin Properties
Key in the value of "client_email" value into OAuth 2.0 Client ID, and value of "private_key" into OAuth 2.0 Client Secret, then Submit.
Google Drive Form Element
With the steps above done, you are now ready to use the Google Drive File form element.
Just configure on which user's Google Drive you want to store to and name the folder accordingly.
Files uploaded will follow the same folder structure as the native File Upload element. Here's the sample screenshot in Google Drive.