To automatically empty your WordPress trash using the EMPTY_TRASH_DAYS constant, you need to add a line of code to your WordPress site’s wp-config.php file. The wp-config.php file is located in the root directory of your WordPress installation, and it contains important configuration settings for your site.

To automatically empty your WordPress trash, you need to add the following line of code to your wp-config.php file:

define('EMPTY_TRASH_DAYS', 7);

In this code, the EMPTY_TRASH_DAYS constant is defined and set to 7, which means that WordPress will automatically empty the trash every 7 days. You can change this value to any number of days that you want.

After adding this line of code to your wp-config.php file, you need to save the file and upload it to your server. This will apply the new trash settings to your WordPress site, and your trash will be automatically emptied according to the schedule you specified.

Keep in mind that automatically emptying your WordPress trash can permanently delete your trashed posts and other content. If you want to retain your trashed content, you can either disable automatic trash emptying or periodically manually empty your trash.

I hope this helps! Let me know if you have any questions.