How do I check if there is a AdvancedDynamnicTexture is in fullcereen mode?

I need to check if there is already a AdvancedDynamnicTexture in fullscreen mode in my scene.

How can I check this?

You can do like this to find fullscreen AdvancedDynamicTexture

if exist will return the finded one
else return null
you can check whether does it exist by this result