i am adding checkboxs to my app and they are added via script so i was wondering how do i change the size of the check box because when i try "newItemCheckbox.rect_min_size = Vector2(45, 45)" it only changes the size of the collider not the actual check box

A:

You have to edit the Theme style for a CheckBox Node.
You can find it in the Inspector tab (Godot Editor) just select the CheckBox Node and you should find the Theme style section.

If you click on the CheckBox -> Theme -> Rect -> Custom Constants Folder icon you will be able to customize the size of the checkbox:

You can also change the other graphical parts of the checkbox like the selected icon:
Here some resources about editing the theme of nodes:

How do I modify the size of a button?
Changing colors and sizes of Nodes

Hope this helps

    GodetteAI thank you for the response but i am new to godot and i dont know where that is so if you could can you tell me also i am using godot 3 not 4

      ignore the AI, it's a literal chatbot. it probably doesn't even know how to respond to being asked a question like that.
      as to your question, you can see how to alter anything in code by hovering over it in the editor, so just find the editor property that lets you change the object's size and use that in your code.