Inventory Tooltip problem.

I dont know why but i have a problem in showing a tooltip properly.

As you can see, the tooltip is showing at the back of the slots when i point my mouse in the Item.
I want to make that when i put the mouse in the item, The tooltip will appear in front.
Please help me im new in c#

This is the code function for the position of the tooltip

public void ShowToolTip(GameObject slot)
	{
		Slot tmpSlot = slot.GetComponent<Slot>();

		//if the slot is not empty
		if (!tmpSlot.IsEmpty) 
		{
			tooltip.SetActive(true);
			float xPos = slot.transform.position.x + slotPaddingLeft;
			float yPos = slot.transform.position.y - slot.GetComponent<RectTransform>().sizeDelta.y - slotPaddingTop;
			
			tooltip.transform.position = new Vector2(xPos,yPos);
		
				}

You just need to SetAsLastSibling when the tooltip is shown and it’ll move to the bottom of the list and therefore to the front of UI on screen.