Go to admin.google.com
Google has a detailed guide here - https://support.google.com/a/answer/7281227
But I have created a more visual guide below.
Click on "Security"
At the bottom on security - click on API Permissions
Click on "Trusted Apps"
Click on + Yellow Sign to add a trusted app
Select 'Web Application"
You will need to enter Google Client ID of 10xCRM here - 131939504787-c08ttvr4n6j6pnv607gf66tadb66afub.apps.googleusercontent.com