This members-only tutorial provides the steps to add a section on single posts to display 4 random posts (excluding the current one) in the same category/categories as the current post for a custom "related posts" functionality in Oxygen.
We shall add the PHP code for this in a Code Block to
retrieve the current post's categories
store the array of category IDs in a variable
get comma-separated category IDs in a variable
write a WP_Query arguments array
write a basic loop to show post titles
and finally replace the above loop with PHP and CSS from the default Easy Posts component's preset.
Edit the Template that applies to single blog posts with Oxygen.