Did you compiled it from source? Make sure that indi is properly installed otherwise KStars is build without ekos. You can try use my build script gitea.nouspiro.space/nou/astro-soft-build
I have checked the Settings/Configure Toolbar/ menu and the first three were selected, but the Telescope Toolbar wasn't.
I selected it and restarted Kstars but still no Ekos menu.
Yes, I compiled it from source, which is something I have done maybe 50 or more times over the last 5 or so years.
As mentioned indi-sx is not building properly but everything else appears to be; if you ignore all the usual warning messages that the compiler gives.
His point is/was that you need to compile and install the INDI libs before you compile kstars. Else there might be mismatches in header definitions or library symbols etc...