"Lea128_Household_Besties to Lovers.zip" appears to be a user-created Save File or Custom Content (CC) pack for , likely created by a member of the community like Lea (possibly Lea Martinez or a similar creator).
If you have downloaded a file like this, you typically install it by: the folder. Lea128_Household_Besties to Lovers.zip
Based on the file name, this specific download likely focuses on the popular trope, which is a staple in Sims storytelling and legacy challenges : "Lea128_Household_Besties to Lovers
Opening your in-game Gallery and selecting "My Library" (be sure to check "Include Custom Content" if the Sims look different than the base game). Lea128_Household_Besties to Lovers.zip