In the Quartus Prime Pro/Platform Designer 18.0, I want to execute the tcl command, "package require qsys", or "package require -exact 18.0", successfully.

I have tried in a tcl script, in tools->Tcl Console, in Quartus Prime Pro and in Platform Designer, as well as in quartus_sh, but the package is never found. ​Where and what should be typed to load ...