AdSense ads below post for old classic Blogger template

There are still bloggers who use the old classic Blogger template, some because they have too much customization and too attached to it, and some because they choose to use custom domain and host on their own. Got a guestion on how to add adsense text link ad in below some specific posts.You cannot add AdSense ads only below the post you choose. There is a way to add ads below the post, but you