godot key tap and key hold how to?

Question

if Input.is_action_just_pressed("jump") and is_on_floor():
    jump_timer += delta
    current_speed = crouchspeed
    
elif Input.is_action_just_released("jump") and is_on_floor():
    animation_player.play("headbob when jumping")
    if jump_timer >= 1:
        velocity.y = jump_velocity
    elif jump_timer <= 1:
        velocity.y = wall_jump_velocity

this is my new script and here i was trying have to player jump higher when the key is held for more than a second, i tried doing this with a timer but it seems like i dont know how to make one.