Detect double jump?

This is not a request. I am simply asking you guys to point me in the right direction cause i would like to know how to detect if spacebar has been pressed twice quickly for a double jump. I dont need the double jump its self cause I know how to script that. Im asking how would my script detect if a person double tapped spacebar?

I know this is already answered but the solution up there is terrible, in my opinion.

It's best to check if the player is grounded before letting them jump again.

repeat wait() until game.Workspace:FindFirstChild(game.Players.LocalPlayer.Name) --WaitForChild could be better.
--Defining variables--
plr = game.Players.LocalPlayer.Character["Left Leg"] --Define the left leg
p = game.Players.LocalPlayer --Define the player
ks = {} --Table for keystrokes
ip = game:GetService("UserInputService") --Define user input service
jump1 = false --Debounce
jump2 = false --Debounce

function isGround(hit) --Define function for checking if hit is the floor
	if string.lower(hit.Name) == "baseplate" or string.lower(hit.Name) == "ground" or string.lower(hit.Name) == "floor" or string.lower(hit.Name) == "floor" then --This line could be skipped, I just find it better to tag what is ground, so you can't jump off of non cancollide parts
		return true --Return that it's on the floor
	else return false --Not?
	end
end

function plrGrounded() --Define the function for creating the ray to find the ground
	local ray = Ray.new(plr.Position, Vector3.new(0, -10, 0)) --Create the ray
	local hit, position = game.Workspace:FindPartOnRay(ray, plr.Parent) --Define hit and position, ignoring the player
	if  (position - plr.Position).magnitude <= 1.5  and isGround(hit) then return true else return false  end --If the player is really close to the ground and the function isGround returns true then return true, if not then return false
end

inp = coroutine.wrap(function() --Define coroutine for input detection
game:GetService("RunService").RenderStepped:connect(function()	--Look for input every frame
	ip.InputBegan:connect(function(k,p) --Input start
			ks[k.KeyCode] = true --This key is pressed
		end)
		
	ip.InputEnded:connect(function(k,p) --Input end
			ks[k.KeyCode] = false --The key isn't pressed
		end)	
	end)
end)

sj = coroutine.wrap(function() --Second jump coroutine
	game:GetService("RunService").RenderStepped:connect(function() --Run once per frame
		if jump1 == true and jump2 == false then --if the first jump is true and the player hasn't jumped twice
			wait(0.1) --small pause to prevent a 'launch'	
			if ks[Enum.KeyCode.Space] == true then --If space has been pressed
			jump2 = true --Second jump is true
			plr.Velocity = plr.Velocity + Vector3.new(0,25,0) --Apply the second jump
			end
		end
	end)
end)

--Run--
inp()
sj()

p.Character.Humanoid.Jumping:connect(function() --First jump function
		jump1 = true --First jump is true
		repeat wait() until plrGrounded() == true --Wait until the player is grounded
		jump1 = false --Jump 1 isn't true
		jump2 = false --Jump 2 isn't true
		
end)