This is my code I use to do it, it does not remove the default loading screen no matter me testing in studio or in game.
local Players = game:GetService("Players")
local ReplicatedFirst = game:GetService("ReplicatedFirst")
ReplicatedFirst:RemoveDefaultLoadingScreen()
local player = Players.LocalPlayer
local playerGui = player:WaitForChild("PlayerGui")
playerGui:SetTopbarTransparency(0)
local screengui = script:WaitForChild("Sprites"):Clone()
screengui.Parent = playerGui
You can’t remove it, you can only make it last shorter by putting something inside ReplicatedFirst and calling the :RemoveDefaultLoadingScreen() function. Other than that, there is not much you can do about it.