Outline from Mask for OBS not showing up

[JoshuaRossChristie]

I'm trying to make a mask in Photoshop for Streamlabs OBS but the png file isn't showing the color from the rectangle I'm trying to export. How do I do this? Is another layer required? https://www.youtube.com/watch?v=by255Fj6AIQ&t=726s

that is the link I am trying to follow but I can make my rectangle but I can't seem to get it to export like. him. it also doesn't show the border help would be appreciated thanks.

[Bojan Živković]

In video I do not see how file is exported. However, with only rectangle layer visible and transparency around it you can use Save As, Export > Export As or legacy Save for Web to export/save PNG file with transparency.