Below information is mentioned on play console
To associate your app with a website domain, copy and paste this snippet into your Digital Asset Links JSON file. If you already have a non-empty JSON file, merge this snippet with the existing statements according to documentation. Digital Asset Links JSON file is required if you want to use Android App Links to direct mobile web users to your app.
I am getting an error that my domain is not verified and I am unable to find and update this JSON file while setting up deeplink. Please note I am not using firebase dynamic links as that is going to be deprecated soon
Any help in how to verify the domain is appreciated