The export add-on for Artlantis 2.0 is a download from the Abvent web site.
Attached is the 1.2 and earlier add-on for MacTel from the Add-Ons > Import-Export folder - but I believe it requires some support files to be installed in the Support folder. You may find it fastest to do a repair/reinstall of AC 11 from your original media and then apply the latest hotfix if this doesn't work.
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB