This module is depending upon a deprecated library, yet claims to be Drupal 10 ready. The core/jquery.once asset library is deprecated in Drupal 9.3.0 and will be removed in Drupal 10.0.0. The core/once library should be used instead. See https://www.drupal.org/node/3158256 →
Looking at simple_popup_blocks.libraries.yml, the dependencies list "core/jquery.once" instead of "core/once".
See https://www.drupal.org/node/3158256 → and https://www.drupal.org/project/drupal/issues/3183149 → for details on how to fix.
Closed: duplicate
3.1
Code
Nevermind, is a duplicate of https://www.drupal.org/project/simple_popup_blocks/issues/3367595 🐛 Remove useage of $(...).once, as it is removed in drupal 10 Closed: duplicate