Proxmox: Trouble with permissions of data in a mountpoint for a lxc (audiobookshelf) - eviltoast

I am moving from an debian-server (odroid) to a proxmox-server. I have a 2tb-ssd for some media in my proxmox, so that is what i did:

  1. i mounted the smaba-share from my old server in proxmox (not in the lxc “ausiobookshelf”)
  2. i moved the data from the old server to the lxc-mountpoint “audiobooks” on my proxmox

This worked but now i have trouble to give permissions. In proxmox i can edit the permissions but there is no user “audiobookshelf” in the proxmox-root. In the lxc i have the user “audiobookshelf” but i have no rights to edit the permissions.

Question: What is the best solution to move data to lxc-mountpoints regarding the permissions? Should i use a systemwide user or group? Or should i mount the samba-share from the old server in the lxc?

audiobookshelf is only the beginning. SABnzbd and jellyfin will follow so i ask in common… ;)