why do I get HTTP 0 (HTTP 400 (HTTP/1.1 400 UserOffline)) when the player is clearly online?

local Frame = script.Parent
local Gui = Frame.Parent
local FriendText = Frame.Friend
local Join = Frame.Join
local TeleportService = game:GetService("TeleportService")
local player = Gui.Parent.Parent
local Player = player

Join.MouseButton1Click:connect(function()
    local Name = FriendText.Text
    local ran, PLR_ID = pcall(function()
        return game:GetService("Players"):GetUserIdFromNameAsync(Name)
    end)
    print(PLR_ID)
    if ran then
        print(PLR_ID)
        if player:IsFriendsWith(PLR_ID) then
            print(player.Name.." is friends with "..Name.."! Initiating Teleport...")
            warn("Teleporting...")
            local function followPlayer(player, targetplayer)
                local success, errorMsg, placeId, instanceId = TeleportService:GetPlayerPlaceInstanceAsync(targetplayer)--
                if success then
                    TeleportService:TeleportToPlaceInstance(placeId, instanceId, player)
                else
                    print("Teleport error:", errorMsg)
                end
            end
            followPlayer(Player, PLR_ID)--
        end
    end
end)

ignore the variables lmao, this throws the error: HTTP 0 (HTTP 400 (HTTP/1.1 400 UserOffline)) however, the player is in fact playing the game. This is between two seperate games, but in the shared universe.