Currently, the positive compatibility support of this plug-in refers to an old version of ActionBarAPI that only supports up to mc 1.14. This 'fork' however seems to support up to 1.19, so I should support that as well: https://www.spigotmc.org/resources/actionbarapi-1-8-1-19.86006/

Support for this new ActionBarAPI will be added in KCI 12.9 or 13.0 (probably 12.9).

Note to myself: don't forget to update the wiki

It will be done in KCI 12.9