In Katalon Store, TestRail Plugin shows status as Expired even though you’re an Enterprise user:
Uninstall and Re-install the plugin
Deactivate and Activate your account in Katalon Studio then Reload Plugins
In case the Plugins window shows that you have successfully installed the TestRail plugin on your KS as evidenced by the success confirmation on your window, you can disregard the "Expired” message" on Katalon Store as this does not affect your license. KS still installs the plugin since you have an active license.