Adding music to Plex or Plexamp using a 3rd party product like iMazing

Server Version#: latest
Player Version#: latest
Is there a possibility to add and remove music to PLEXAMP (or Plex) using 3rd party product like iMazing?

Nope. iMazing adds files to the device, not to the Plex server.

If Plex for iOS can play back local files, as Android can, then you could add files to the device with iMazing and play them. But, they won’t be part of your Plex library.