calibre, wordpress: Services tries to start before app is installed

Version: 20.17~bpo10+1 on stable virtualbox

I have not installed Calibre app, so when I visit the app page I get an installation prompt, as expected.

# journalctl -u calibre-server-freedombox
-- Logs begin at Fri 2020-11-06 02:12:01 UTC, end at Fri 2020-11-06 02:14:32 UTC. --
Nov 06 02:12:05 freedombox systemd[1]: Starting calibre Content Server...
Nov 06 02:12:05 freedombox sh[517]: /usr/bin/sh: 1: calibredb: not found
Nov 06 02:12:05 freedombox systemd[1]: Started calibre Content Server.
Nov 06 02:12:05 freedombox sh[539]: /usr/bin/sh: 1: exec: /usr/bin/calibre-server: not found
Nov 06 02:12:05 freedombox systemd[1]: calibre-server-freedombox.service: Main process exited, code=exited
Nov 06 02:12:05 freedombox systemd[1]: calibre-server-freedombox.service: Failed with result 'exit-code'.
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Service RestartSec=100ms expired
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Scheduled restart job, restart c
Nov 06 02:12:06 freedombox systemd[1]: Stopped calibre Content Server.
Nov 06 02:12:06 freedombox systemd[1]: Starting calibre Content Server...
Nov 06 02:12:06 freedombox sh[562]: /usr/bin/sh: 1: calibredb: not found
Nov 06 02:12:06 freedombox systemd[1]: Started calibre Content Server.
Nov 06 02:12:06 freedombox sh[579]: /usr/bin/sh: 1: exec: /usr/bin/calibre-server: not found
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Main process exited, code=exited
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Failed with result 'exit-code'.
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Service RestartSec=100ms expired
Nov 06 02:12:06 freedombox systemd[1]: calibre-server-freedombox.service: Scheduled restart job, restart c
Nov 06 02:12:06 freedombox systemd[1]: Stopped calibre Content Server.