$schemamarkup = get_post_meta(get_the_ID(), 'schemamarkup', true); if(!empty($schemamarkup)) { echo $schemamarkup; }

How to Install Gnome Extensions App in Ubuntu Gnu/Linux Distro

GNU/Linux Ubuntu Installing GNOME Extensions App Guide

Hi! The Tutorial shows you Step-by-Step How to Install GNOME Extensions Flatpak App in Ubuntu GNU/Linux Desktops.

And GNOME Extensions App for Ubuntu handles Updating Extensions, Configuring Extension Preferences and Removing or Disabling them.

Especially relevant: starting from the GNOME 41 release the Shell Extensions are not any more manageable by the Tweaks but just with the App.

How to Install GNOME Extensions App Flatpak on Ubuntu - Featured

GNU/Linux Ubuntu GNOME Extensions Application Installation Guide