Already have an account, this is a guide on how to add a new site in AdSense. It used to be a lot easier if you already have a verified website/blog and you can add a new one anytime.
Since the change of rules and regulations, every new site you added will be going through the same rigorous process for verification as the first one so, you can continue to use or run Ads for your websites
FIRST, Search for AdSense and sign in to your account
SECOND, On the left side of your dashboard, you will have options and click on sites
THIRD, Click on the add site button
LASTLY, After entering your Domain or URL you will be given a code to paste or add it just below the <head> tag
I have already written a blog post for each of the platforms I cover on my website. I’ll be linking to each of those posts from here and choose one depending upon your need