@PinkButterfly716 If you want to use the packs that say "manage on Steam" next to their names, you'll need to play the game through Steam and also uninstall the EA App version of Sims 4. Since it appears you have multiple issues here, I'd strongly suggest doing a clean uninstall before reinstalling through Steam. Here's how:
Once you've downloaded the game through Steam, plus any packs you own there, you can sign into the EA App and install the packs you own there, but NOT a second copy of the base game. Everything should work together going forward.
I couldn't get that to work either. I just rebought the packs on steam since EA was not willing to help. I won't buy any DLC from EA app again, I have learned my lesson in a costly way. ☹️
