How to detect drag if pressed a UMG button?

Hi, I was working on a android game, I wanted to create a drag and drop functionality. On overridable functions, I used on mouse button down (use mouse for touch is enabled in project settings), then detect drag if pressed, here instead of using any keyboard or mouse key events I want to use touch event on a button, but how to do that? how can I put the button pressed event into the detect drag if pressed blueprint?

Please help me if anyone can, thanks in advance.