You can use Humanoid.Jump to trigger a jump. This is a bool value that when true has the character jump. This will reset to false so no worries getting it to reset.
script.Parent.Touched:Connect(function(p)
if p.Parent:FindFirstChild(“Humanoid”)then
p.Parent.Humanoid.JumpPower = 70
p.Parent.Humanoid.Jump = true --This is the added code.
wait(5)
p.Parent.Humanoid.JumpPower = 50
end
end)