startup.lua

commands.exec("gamerule commandBlockOutput false")
commands.exec("/scoreboard objectives add JustJoined stat.leaveGame")

local function teleport()
    commands.exec("/tp @a[score_JustJoined_min=1] -220 79 276")
    sleep(0.01)
end

local function update()
    commands.exec("/scoreboard players set @a JustJoined 0")
    sleep(0.01)
end

while true do
parallel.waitForAny(teleport, update)
end