Resized preview

I worked on a mobile app for couple of months now, I have like 15 artboards with interactions etc. 

My artboards size is 1080 x 1920,  now when I share the prototype it is too big for the screen, the users have to zoom out, which not everybody will figure out (I want to put the link in my portfolio).

Is there anyway to setup the preview slacced down? 

or maybe I can somehow eazily resize everything without having to do a tone of work? 

Thanks.