1-Open new file and draw a polyline.
2-Select "Simple Extrude command".
3-Click on the profile,polyline is highlighted.
4-Now right click and see option "Use compound Profile" is greyed out it can't be selected.
5-If a profile is already selected it is not possible anymore to choose the "use compound profile" command. It should be available also after the first profile is selected.
Use Shift key to select additional profiles. See "Extruding Multiple Profiles" part of the help topic: http://doc.imsidesign.com/articles/#!turbocad-2018-user-guide-publication/simple-extrude-1