Main menu cinematic

Hi,
I’m doing an archviz project and i need HELP !!! (blocked for days :mad:)
I have a simple main menu with 3 buttons :

PLAY : launch the game ( free walk)

TRAILER : launch the cinematic ( from the sequencer player)

QUIT : to quit

I want to click on my trailer button to launch my sequencer cinematic from the main menu BUT I DON’T KNOW HOW TO DO THAT…

Thanks if someone could help.