The file is a "Sims 4 Import" package commonly found on community modding sites. These archives are designed to allow players to easily install a specific Sim with all their custom content (CC) pre-packaged. Typical File Content
In the game's Gallery/Library, ensure you check the "Include Custom Content" box on the left-hand filter panel, or the Sim will not appear. Required Cheats for Editing
If you wish to further modify the Sim's physical attributes after importing, you will need to enable : Open the cheat console ( Ctrl + Shift + C ). Type testingcheats true and hit Enter. Type cas.fulleditmode and hit Enter. Shift-click the Sim and select "Edit in CAS." The file is a "Sims 4 Import" package
Copy all files ending in .householdbinary , .trayitem , and .s4i into your Tray folder.
The zip file usually contains two main components required for the Sim to appear correctly in your game: Required Cheats for Editing If you wish to
Copy all .package files into your Documents > Electronic Arts > The Sims 4 > Mods folder.
A collection of .package files. These include the specific assets used to create Ai Uehara's look, such as: Shift-click the Sim and select "Edit in CAS
Use a tool like 7-Zip or WinRAR to open the file.