Cron Jobs help ? Shell users only!

Hey guy I need help. I have install an application that recommend to set a cron job. When i go to my Cpanel - Cron job - creat new cron. I add the title and commanda line but when i hit the save button i get an error "invalid user’ ?? i see the user drop down button but when i click on it its blank. i see below user it say Shell Users Only!! what does that mean? how can i create a cron job??


Edit that user so they’re SSH (Shell) and FTP. If they are not a shell user, they have an invalid shell which won’t run a cron job.