Hi Peter,

There is no official way to migrate custom settings to another Mac, but you can try to export them manually.
All customization is inside two folders:
~/Library/Application Support/Autodesk/AutoCAD 2019/R23.0/local
and
~/Library/Application Support/Autodesk/AutoCAD 2019/R23.0/roaming
Note that the Library folder is Library folder inside user Home folder, you can reach it from Finder, using menu Go->Library.

Don't forget to backup custom AutoCAD settings on target Mac before you migrate folders I mentioned above from another Mac.