Inside the app, click on settings on the left menu and go to ‘Basic’.
Fill in the following 3 compulsory fields:
App Domains: Enter your website details
Privacy Policy URL : Enter the URL of your privacy policy on your website. If you do not have that, create a document on Google Drive (or anywhere) and put a link here. This doesn’t need to be legally perfect, you just need a URL here.
Category : Choose the right category as per your business.
Click on save changes and then Activate the App using the toggle button on the top of the screen
Click on the APP ID on the top of the screen to copy it.