Follow below mentioned steps to get your Google Client ID and Secret Key:

1. Go to Google Developer portal
2. If you have just created Google Developer account, you need to click on Agree and continue button to get into your Google Console account. However, if you have already accepted Terms & Conditions, then skip Step 2 & 3, and follow the tutorial from Step 4
   
3. After agreeing to the Terms and Conditions, click on Go to credentials 
4. A default project titled as My Project will start reflecting in your account, if you want, you can continue with the same project and follow the tutorial from Step 8. However, you can also create your own new project. For creating a new project, click on My Project dropdown menu present at the top
   
5. It will open select project window, click on “+” button to create a new project
6. Provide a name of your new project and click on Create button

7. Now click on My Project dropdown menu, select All tab, and open your newly created project
   
8. Under Credentials section, select the OAuth consent screen tab 
9. Select an Email address from the dropdown menu, enter Product name (if it is not already set), and click on Save button
10. Select Credentials tab, click on Create Credentials button and select OAuth client ID
    
11. Select Web Application as the application type 
12. In the Authorized JavaScript origins field, enter the URL – https://your-domain-name.com, While in Authorized redirect URLs field:
    1. Enter URL –   Your redirect URL (Get from SheetPress Settings page)

    

13. Your Client ID and Client Secret key will appear