How do you make an animated HUD?

Hi, I’m trying to make an animated HUD in my game. Basically, I want to show a thumbnail for whatever gadget the player has picked up, on the HUD. The thumbnails all have a little animation, like so. (attached)

I have these animations in video format, and I also have the “mask” for it in video format (to remove the black background). I have searched on the forums but I can’t seem to find the solution. If I add an image widget and use the Media Texture on it, I can’t remove the black background (or don’t know how to). Also, every time I close the editor, the media player loses its reference to the video and I have to load it and save it again. Unless I do so, it just displays a blank. I tried using the media texture in a material (Material Domain : User Interface), but didn’t have any luck. While dragging the media texture in the material BP, the cursor changes to the “not allowed” sign. If I still drag it in though, a blank TextureSample Node is created. Connecting that to “Final Color” does nothing.

I am unsure how to proceed. I’m not even sure if I have the assets in the correct format. Is this sort of thing implemented using animations in video format? If so, how? If not, what format should I have the animations in and how should I proceed from there? I’m stuck, and any help is greatly appreciated. Thanks!