(Looking for help) AR - fade out between intro(video) and move UI

Regards to all.

I would like to ask you all if you are able to help me with the AR application I'm currently working on. Before the sessions, I added an introductory video before the moveUI offered me, however, the video is immediately over and immediately offers me the moveUI. What I want to do is to have some fade effect that will make a slight transition to video and moveUI. If someone knows how to do it, please help me. Below I'll deliver a video to look at. Thank you in advance.