falling player while platform move

Question

Hi i have problem because when my player character jump on platform while moving my character falling (image below)

Here is moving script

    sprint = false;
    iswalk = false;

    Vector3 direction = new Vector3();
    direction.x = 0;
    direction.z = 0;

    var aim = camera.GlobalTransform.basis;

    if (Input.IsActionPressed("ui_left"))
    {
        direction -= aim.x;

        //Rotation
        GetNode<Spatial>("Armature").Rotation = new Vector3(0f, Mathf.LerpAngle(GetNode<Spatial>("Armature").Rotation.y, Mathf.Atan2(velocity.x, velocity.z), delta * 7f), 0f);

        //Animation
        iswalk = true;
    }

    if (Input.IsActionPressed("ui_right"))
    {
        direction += aim.x;

        //Rotation
        GetNode<Spatial>("Armature").Rotation = new Vector3(0f, Mathf.LerpAngle(GetNode<Spatial>("Armature").Rotation.y, Mathf.Atan2(velocity.x, velocity.z), delta * 7f), 0f);

        //Animation
        iswalk = true;
    }

    if (Input.IsActionPressed("ui_up"))
    {
        direction -= aim.z;

        //Rotation
        GetNode<Spatial>("Armature").Rotation = new Vector3(0f, Mathf.LerpAngle(GetNode<Spatial>("Armature").Rotation.y, Mathf.Atan2(velocity.x, velocity.z), delta * 7f), 0f);

        //Animation
        iswalk = true;
    }

    if (Input.IsActionPressed("ui_down"))
    {
        direction += aim.z;

        //Rotation
        GetNode<Spatial>("Armature").Rotation = new Vector3(0f, Mathf.LerpAngle(GetNode<Spatial>("Armature").Rotation.y, Mathf.Atan2(velocity.x, velocity.z), delta * 7f), 0f);

        //Animation
        iswalk = true;
    }

    if (Input.IsActionPressed("sprint"))
    {
        sprint = true;
    }

    //Animation

    if (iswalk)
    {
        if (sprint)
        {
            move_animation = animator.SetValue(delta, ref move_animation, 1f);
            animationTree.Set("parameters/walk/blend_amount", move_animation);
        }
        else
        {
            move_animation = animator.SetValue(delta, ref move_animation, -1f);
            animationTree.Set("parameters/walk/blend_amount", move_animation);
        }
    }
    else
    {
        move_animation = animator.SetValue(delta, ref move_animation, 0f);
        animationTree.Set("parameters/walk/blend_amount", move_animation);
    }

    // End Animation

    //Jump Animation

    if (Input.IsActionJustPressed("jump") && IsOnFloor())
    {
        velocity.y += 3f;
    }

    if (!IsOnFloor())
    {
        jump_animation = animator.SetValue(delta, ref jump_animation, 1f);
        animationTree.Set("parameters/jump/blend_amount", jump_animation);
    }
    else
    {

        jump_animation = animator.SetValue(delta, ref jump_animation, 0f);
        animationTree.Set("parameters/jump/blend_amount", jump_animation);
    }

    //End Animation

    direction = direction.Normalized();

    velocity.y -= gravity * delta;

    var temp_velocity = velocity;
    temp_velocity.y = 0;

    Vector3 target;

    if (sprint)
    {
        if (IsOnFloor())
        {
            target = direction * 6f;
        }
        else
        {
            target = direction * 4f;
        }
    }
    else
    {
        target = direction * 2f;
    }

    int acceleration = 0;

    if (direction.Dot(temp_velocity) > 0)
    {
        acceleration = 2;
    }
    else
    {
        acceleration = 6;
    }

    temp_velocity = velocity.LinearInterpolate(target, 4 * delta);

    velocity.x = temp_velocity.x;
    velocity.z = temp_velocity.z;

    velocity = MoveAndSlide(velocity + GetFloorVelocity(), Vector3.Up);

Here is my scene tree

Here is how player react while platform moving