Help with Lerp Hud

Help me to deal with Lerp. I don’t understand how to add lerp to HUD


local function HUDCLIP()
	if LocalPlayer():GetActiveWeapon():IsValid() and LocalPlayer():GetActiveWeapon():Clip1() then
		return LocalPlayer():GetActiveWeapon():Clip1()
	else
		return 0
	end
end

local function GETMAXAMMO()
	if LocalPlayer():GetActiveWeapon():IsValid() and LocalPlayer():GetActiveWeapon():GetMaxClip1() then
		return LocalPlayer():GetActiveWeapon():GetMaxClip1() 
	else
		return 0
	end
end

local function HUDAMMO()

	local H = 84 * HUDCLIP()/GETMAXAMMO()

	if H < 21 then
		HUD.AMMOCOLOR = Color(255,0,0,255)
	elseif H < 42 then
		HUD.AMMOCOLOR = Color(211, 84, 0,255)
	elseif H < 63 then
		HUD.AMMOCOLOR = Color(255,150,130,255)
	elseif H <=84 then
		HUD.AMMOCOLOR = Color(255,255,255,255)
	end

	if HUDCLIP() > 0 then

	if H  == 84 * HUDCLIP()/GETMAXAMMO() then
	H  = H 
		else
	H  = Lerp(0.2, H , 84 * HUDCLIP()/GETMAXAMMO())
	end

	local lerp = math.Clamp(H, 0, 100)


	draw.RoundedBox(2, 300, (ScrH() / 2) * 1.76, 42, 86, HUD.BG)
	draw.RoundedBox(0, 303, (ScrH() / 2) * 1.98 -lerp, 36, lerp, HUD.AMMOCOLOR)

	surface.SetDrawColor(Color(255,255,255,255))
	surface.SetMaterial(Material(Icon.Ammo))
	surface.DrawTexturedRect( 303, (ScrH() / 2) * 1.965 -lerp, 36, 10)

	draw.SimpleTextOutlined( math.Round( HUDCLIP()), "dayz", 320, (ScrH() / 2) * 1.9, HUD.TEXT, 1, 1, 1, HUD.TEXTBORDER )
		else
	end

end