Legit Sims 3 from Origin and trying to install expansion

I have bought a legit The Sims 3 base game disc years ago but lost it. I've registered it on Origin and one day I saw that I was able to download off Origin because I registered it. It works great. I've tried downloading Into the Future but I can not figure out how to drag the files into The Sims 3 Origin version since they look different. Can someone help? 

Hi there, and welcome to the Games4theworld Forum!

Please, take a look at the guide for installing The Sims 3 here:
https://games4theworld.forumotion.com/t1171-must-read-how-to-install-the-sims-3-correctly

What you need to do is install Into the Future by double clicking the Autorun inside of the folder you extracted.
Then, download the Manual Patch from the Step 2 and double click it.
When it's done, download the Ultimate Fix, and take the .dll and .exe inside the #Crack folder (only this folder, you can ignore the rest of them), and copy them to Program Files (x86)\Origin Games\The Sims 3\Game\Bin. Make sure to select "Copy and Replace" if prompted.

That's all you need to do. I hope I was clear enough. Please, do let us know how it goes. Good luck!