Android phone as plex music server to use with echo dot

[bigredlions]

I recently bought an echo dot. I'd like it to play my music in my car. I'd like to set up the phone as a plex server and use the echo to control it. Has anyone set up an android phone to be a plex media server. All my music is on my phones sd card and the dot seems to work ok with Plex on my PC. I've downloaded the plex app and it goes to my PC Plex server. I can't see of anyway to open a new library item for my phone. Any help would be appreciated. Thanks