Use a program like 7-Zip or WinRAR to open the downloaded ZIP or RAR file.
In The Sims 4 game options, go to Other and ensure "Enable Custom Content and Mods" and "Script Mods Allowed" are checked. Sasha's Initiation (Final Version) Download for...
Move the .package and .ts4script files into your Documents > Electronic Arts > The Sims 4 > Mods folder. Use a program like 7-Zip or WinRAR to
"Sasha's Initiation" appears to be a specific quest or "Useful Feature" content pack for the mod in The Sims 4 . Key Details & Download "Sasha's Initiation" appears to be a specific quest
Do not place the files more than one subfolder deep (e.g., Mods/SashasInitiation/ is okay, but Mods/Folder1/Folder2/SashasInitiation/ will not work).
The "Final Version" typically includes the complete set of progression-based interactions and animations intended for that specific storyline or "initiation" sequence.