Execute php in posts [WordPress]
When you take a look at the post body you see short codes within [ and ] brackets such as [example]. I cant paste the same short code here as it would execute. So that’s how you add a link to your php code that is written and managed all stored in the database.
Though, there are so many execute php plugins, I prefer Shortcode Exec PHP plugin. The plugin is regularly updated, maybe not every month but when new WordPress update rolls out those kind of changes. You can manage your php code snippets on the plugin settings page, found under Tools on your WordPress admin dashboard, as shown below,