Use embedded Ace code editor. Ace is a highly capable code editor for the web. Recommended Yes Module page https://www.drupal.org/project/ace_editor Module tags #Enhancement Stability Beta Tags #Layout Related modules CKEditor 5 Module issues Ignore <!DOCTYPE> warning #Layout [Issue] Add reusable option to inline block creation [Issue] Add an option to fork a reusable block to a non-reusable inline-block (and optionally delete the reusable block IF it's not used elsewhere [Issue] Use layout builder for content add/edit form [Module] Block title link [Module] Ace Code Editor