Click the "Search (/) for resources, docs, products, and more" field.
Type "youtube"
Click here.
Click "ENABLE"
Click "OAuth consent screen"
Now we create a OAuth consent screen to show user our App info.
Click "External"
Click "CREATE"
Click the "App name" field.
Type Your App name
Click here.
Click the user support email shown here
Click the "Email addresses" field.
Enter your Email
Click "SAVE AND CONTINUE"
Click "ADD USERS"
Click this field.
Enter the email you want to test the App with (up to 100 emails)
Important: You will get error if you did not login with email within Test users
Click "ADD"