Find out if an offline player is in a group or not?

Hi, I'm making an EXP database, and want to find out wether or not the searched player in the database is in my main group or not, and what it's rank is. I use data stores in the script.

-- Enable Check

local DSService = game:GetService("DataStoreService")
local PlayerDataStorage = DSService:GetDataStore("vpqARwiBjdvaStxoZmCxUxxd")



script.Parent.MouseButton1Click:connect(function()
	ScanName = script.Parent.Parent.TextBox.Text
	script.Parent.Parent.TextBox.Text = "Name Here"
	script.Parent.Parent.Loading.Visible = true
	local PlayerDataSave = ScanName.."vpqARwiBjdvaStxoZmCxUxxdPlayerSave:"
	PlayerEXP = PlayerDataStorage:GetAsync(PlayerDataSave.."EXP")
	local PlayerCOMMENT = PlayerDataStorage:GetAsync(PlayerDataSave.."OFC")
	PlayerID = PlayerDataStorage:GetAsync(PlayerDataSave.."ID")
	if PlayerEXP then
		script.Parent.Parent.Loading.Text = "Data found. Viewing..."
		wait(1)
		ViewData()
		script.Parent.Parent.Loading.Visible = false
		script.Parent.Parent.Loading.Text = "Loading..."
	else
		script.Parent.Parent.Loading.Text = "Data not found. Aborting..."
		wait(1)
		script.Parent.Parent.Loading.Visible = false
		script.Parent.Parent.Loading.Text = "Loading..."
	end
end)

function ViewData()
	script.Parent.Parent.Parent.DataView.PlayerName.Text = "Player Name: "..ScanName
	script.Parent.Parent.Parent.DataView.PlayerEXP.Text = "EXP: "..PlayerEXP
	local HTTPID = "http://api.roblox.com/users/"..PlayerID
	script.Parent.Parent.Parent.DataView.PlayerRankAI.Text = "Rank: "..HTTPID:GetRoleInGroup(2842013)
	script.Parent.Parent.Parent.DataView.PlayerId.Text = ("UserId: "..PlayerID)
	script.Parent.Parent.Parent.DataView.Visible = true
end

At line 33 and 34 I tried the "http://api.roblox.com/users/"..PlayerID" way, however, it did not work, neither did putting the player ID in directly.

Is there anyway I can find out a players rank in a group without the player being online? Aswell if the player is in a group?