Make certain user load certain character?

I'm currently trying to get it so where a certain user will have their own personal custom character loaded in game. I already have the character ready but I'm not sure how to get it to make it the user's character.

Here is the script I have so far.

--Player Stuff--
local player = game:GetService("Players").Screaming_Monkeys
local chara = player.Character

use player:ClearCharacterAppearance() then player:LoadAppearance(playerId):

--Player Stuff--
local player = game:GetService("Players").Screaming_Monkeys
player:ClearCharacterAppearance() 
player:LoadCharacterAppearance(PLAYER ID YOU WANT) 

The playerId are numbers, you can get it in the link to someone profile (example: my profile is "https://www.roblox.com/users/2479393/profile", so my userId is 2479393), or if you want the if of someone ingame you can get the property userId or characterappearanceid of a player:

--Player Stuff--
local player = game:GetService("Players").Screaming_Monkeys
local id = game:GetService("Players").PLAYERNAME.UserId
player:ClearCharacterAppearance() 
player:LoadCharacterAppearance(id)