the sims 4 does not turn on vacation mode.

@nnatnmk 

Obvious question but do you have either the Outdoor Retreat or Jungle Adventures game packs?  Without them, you won't get the vacation options on the phone as they are the only vacation worlds.

If you do have one or both of them, have you tried checking on a computer to see if the vacation options there?

I'm not sure if this makes a difference in whether the options will show up, but does your sim have any vacation days in the career panel?  If you have none, then you might not be able to take a vacation without quitting the career.  I do know that sims can go on vacation if they do not have a career.  This is just a guess though as I have had sims and go on a vacation and run out of vacation days while there but I have never tried scheduling one when they have no days.

If you have tried that and they don't show up, then you may need to repair your game and also delete the localthumbcache file in the Sims 4 folder as well.  If you are not playing on a PC or Mac, you can't do that but you can reset the cache on the consoles by powering down your system, unplugging it for a few minutes and then plug it back in and restart the system and the game.

Hope this helps.