I am trying switch accounts

Remnil7​  What exact step are you trying to do?  Please post a screenshot and/or link the guide you're using.  To play through Steam though, you need to uninstall the EA App version of Sims 4 and reinstall it through Steam, then download any packs you own through the EA App, but NOT a second copy of the base game.

https://www.reddit.com/r/thesims/comments/12o2vuq/combining_steam_and_origin_account/

Remnil7​  Close the game first, and only then open the EA App and click Sims 4 > Manage > Manage add-ons.  You should be able to download your EA App-owned content without reinstalling the base game.

yeah I have tried that I still can't click on the manage drop down button. 

Remnil7​  Clear the EA App's cache, restart your computer, and try again.

https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/

If that doesn't help, uninstall and reinstall the EA App.

If that doesn't help either, please double-check that your Steam and EA accounts are properly linked to each other.  The easiest way to do so is to sign into the EA App with your Steam credentials.  If you land in the correct EA account, they're linked; if anything else happens, let me know.

i tried those and I still can't click on the manage button

Remnil7​  Does the EA App think Sims 4 is installed?  If not, the Manage button might not work.  I'm not saying you should install it through the EA App, only that this would explain the issue.

And again, please tell me whether your EA and Steam accounts are linked to each other as I described.

yes they are linked I login with i with my steam account. and sorta it says it is installed but a steam in top right corner. 

Remnil7​  The Steam logo in the upper-right corner is normal.  The question is why the App isn't letting you download your content.

What happens if you click Add-ons (or DLC) at the top of the Sims 4 product page, above the game title?  Can you download your packs from that list?  Please try it and let me know.

no i cheeked cats and dogs and it only offered me to buy them from both ea and steam