Sims Going to work Please help

If you go into the careers tab in the bottom right of the screen, there should be a button to send them to work.
It's either that or click the little brief case option on their small portrait in the bottom left.

(one of these should work, sorry I haven't played much sims 4 ,but this is what i seem to recall)

Hope this helps

If the work has begun, and they're late for example, you can click on the sim and there must be an option like "Go to work" or something similar.
I'm playing the sims in french so i'm unsure about the exact term but by clicking on the sim you have an option to go to work.