PMS not launching when I click on it

I’m not entirely sure (I’m really not great with all this stuff to be perfectly honest).
But I suppose so.
I guess I do not have the option to ‘add media from my own device’ - in order to watch it on a different device which also has the Plex app installed - which I did have the previous times. The seperate app ‘Plex Media Server’ simply does not do anything when I try to launch it.
If it helps, I’m pretty sure this forum contains the same problem I am currently experiencing: