Can I Plug and Play a Windows SSD on HA on Pi?

I am a noob on HA. I have installed it on a pi4 and it boots from an SSD. I recently installed Plex Server on HA. All of my media is on another SSD which I was using on a PC. Now when I plug the second SSD on Pi, I can’t see it when I try to add it to the library on Plex.