Drag event doesn't work

Hi, I’m trying to make a container that can be dragged with the mouse, I’ve checked out this example:


The problem is that this code doesn’t work on my program, the drag event doesn’t work, but I checked out what would happen if I use it on the “Making your first Phaser 3 game” code and it works perfectly in there. I don’t know why is this happening, only that event isn’t working.