Go to https://console.developers.google.com and log in to the Google Cloud Console using a Google account.

Once signed in, select the drop-down menu at the top-left corner and you will see a list of existing projects.

Click on the New Project link at the top-right corner. 

Once you input the project name, organization and location, select Create.

Under the bell icon at the top-right corner of the page, the notification window will now show your newly created project. Select the Select Project link under your project name.

Click on the + ENABLE APIS AND SERVICES link at the top of the page.

In the search box, enter 'Google Drive API' and click on the corresponding box within the search results list.

Select the Enable button to enable the Google Drive API within your project.  You will now be taken to the project overview page.  Select the Create Credentials button in the top-right corner.  

Before creating the credentials, the OAuth consent screen configurations need to be set up.  Select the OAuth consent screen option in the sidebar to the left.

OAuth Consent Screen

1. User Type - Choose either an internal or external user type and select the Create button. 
2. App Information - Enter details such as app name (no spaces allowed), user support email, app logo (optional).
3. App Domain - Enter app domain-related details such as your website link or organization policy links (optional).
4. Authorized Domains - When a domain is used on the consent screen or in an OAuth client’s configuration, it must be pre-registered here. Enter the following domains by selecting the + ADD DOMAINS button after each:
   1. force.com
   2. visualforce.com
5. Developer Contact Information - Enter email(s) for Google to notify if there are any changes to your project.
6. Select the SAVE AND CONTINUE button.

Scopes 

1. No changes necessary.  Select the SAVE AND CONTINUE button.

Summary

1. No changes necessary.  Select the BACK TO DASHBOARD button.

Select Credentials from the sidebar on the left.

1. Select the + CREATE CREDENTIALS link at the top and select the OAuth client ID option from the drop-down menu.
2. Application Type - Select Web application 
3. Name - Enter your application name.  The name of your OAuth 2.0 client. This name is only used to identify the client in the console and will not be shown to end users. 
4. Authorized JavaScript Origins - Nothing to do here.
5. Authorized Redirect URLs - Enter the authorization URL needed for AdvoLogix to communicate with Google Drive. This URL will contain your organization's My Domain.  The URL structure will look like this:

With Enhanced Domain enabled:

Production - https://[your salesforce my domain]--advpm.vf.force.com/apex/AuthenticateGDrive 

Sandbox - https://[your salesforce my domain]--[your sandbox name]--advpm.sandbox.vf.force.com/apex/AuthenticateGDrive

Without Enhanced Domains:

Production - https://[your salesforce my domain]--advpm.visualforce.com/apex/AuthenticateGDrive

Sandbox - https://[your salesforce my domain]--[your sandbox name]--advpm.[instance_name].visualforce.com/apex/AuthenticateGDrive

6. Select the Create button.

Your OAuth client has been created.  The client ID and secret can always be accessed from Credentials in APIs & Services.  We will need to store Your Client ID and Your Client Secret.  Copy Your Client ID and Your Client Secret to the clipboard and proceed to Google Drive Setup in AdvoLogix.