What's the DataStore key corresponding to a DataStore2 combined key?

How would one find this out? There is no documentation out there for this that I could find.

For example, function setup runs whenever a player joins my game:

local DataStore2 = require(1936396537) --ds2
DataStore2.Combine("Main", "Data")

local function setup(player)
	local data = DataStore2("Data", player)
	
	data:Update(function()
		return 100
	end)
end

The Master Key is Main and the Key I want to access through Roblox's DataStore is Data.

I need this because I'm using DataStore2 in a game and need to access an offline player's data.

I found a thread and tried the answer, but wasn't lucky. I tried many things, such as the following:

--158259 is my uid
local ds = game:GetService("DataStoreService"):GetDataStore("Main/158259")
local d = ds:GetAsync("Data/158259") --nil

local ds = game:GetService("DataStoreService"):GetDataStore("Main")
local d = ds:GetAsync("Data/158259") --nil

local ds = game:GetService("DataStoreService"):GetDataStore("Main/Data")
local d = ds:GetAsync(158259) --nil, datatype string is still nil as well

And many others to no avail.

Help would be appreciated.

For DataStore2, you need to get data by using this

local PLAYER_ID = 100000 -- change this to the player id you want
local STORE_NAME = "Data" -- change this to the DataStore's key, the string which you use in DataStore2(player, string)
local VERSION_GET = "0" -- put the version number you would like to get.
local DataStore = game:GetService("DataStoreService"):GetDataStore(STORE_Name.."/"..PLAYER_ID)
print("Data found!" .. DataStore:GetAsync(VERSION_GET))

Hope this works!