Asking a reader to subscribe or sign up for an email at the bottom of an article is an effective way to convert users and move them up your acquisition funnel. Using the "Utility: Promo Button" block makes this easy!
Simply create a new block using the Promo Button block, add your button color, text, and so forth. You can also choose a URL f you are trying to get readers to subscribe, sending them to a marketing page which discusses the benefits of subscription is a great idea. If you want to add an icon for more visual interest, that's available in the Icon property group.
If desired, you can add a UTM tracking parameter in order to gauge the effectiveness of the promotion. (NOTE: Remember that when a user clicks on a link with a UTM parameter, they will restart their session in Google Analytics.)
Then, you can use Utility Regions in the Block Editor in order to add the block to your article pages. Whether you want it at the top or at the bottom, there is probably a Utility Region for that!