video: https://youtu.be/16-1P1uHTWU

HOW TO MAKE A KICK GUI

Owner only:
local open = script.Parent.TextButton -- the opener
local frame = script.Parent.Frame -- the frame
local player = game.Players.LocalPlayer -- player (you)

if player.UserId == 1719872355 then -- if player id = your id (can change your id) then
	open.Visible = true -- opener will visible
else -- if not
	frame.Visible = false -- both of opener and frame will invisible
	open.Visible = false
end

Opener:
local open = script.Parent -- the opener
local frame = script.Parent.Parent.Frame -- the kick frame
local click = script.Parent["UI Click"] -- the sound when you clicked

open.MouseButton1Click:Connect(function() -- when you clicked the gui
	click:Play() -- the sound will play
	frame.Visible = not frame.Visible -- the kick frame will visible/invisible
end) -- end of task

Kick button:
local kick = script.Parent -- the kick button
local username = script.Parent.Parent.username -- username box
local reason = script.Parent.Parent.reason -- reason box
local click = script.Parent["UI Click"] -- sound

kick.MouseButton1Click:Connect(function() -- when the kick button got clicked
	click:Play() -- sound will play
	game.ReplicatedStorage.kick:FireServer(username.Text, reason.Text) -- the server will be fire
end) -- end

ServerSideService script:
game.ReplicatedStorage.kick.OnServerEvent:Connect(function(plr, username, reason) -- when the remote event got fired
	local player = game.Players:FindFirstChild(username) -- finding player with username
	if player then -- if found player with username then
		player:Kick(reason) -- kick player with reason
	else -- if not
		return -- return
	end
end) -- end