The Zakra Pro Add-On allows you to show Related Posts at the end of a Single Post. Just follow these steps to do so:
Navigate to the Appearance > Customize > Content > Single Post section from your WordPress Dashboard.
Toggle the Enable Related Posts option On.
In the Posts Related To option, select how the related posts should be chosen. The available options are:
Category: Posts related to this category have been selected.
Tags: Posts related to tags have been selected.
Click on Publish.
It is shown in the image below:
