Cant find my sims 4 folder

Just like Jpkarlsen mentioned. Your Sims 4 folder should be in the C:\Users\Username\Documents\Electronic Arts\

However, if it's not there's a couple reasons for this.

1. Maybe you did a factory reset of Sims 4 and need to play Sims 4, so that the game recreates the folder.

2. It has been moved for some odd reason. (I've had this happen after an update.)

To find where the folder went, search your computer for Sims 4. - Click Start and in the Search bar, search for Sims 4.

The computer should give you some results of where to find your folder. Then you can move it back to the Documents\Electronic Arts folder. - To move the folder, right-click on Sims 4, select Cut, and Paste it back into the Electronic Arts folder.

After your Sims 4 folder is back where it needs to be, the game should recognize it along with your Saves folder and all the rest of the Sims 4 files and folders, and you can install the Mods into the mods folder from there.