Try to apt-get install hplip when you have in the system python >=3.8 (https://packages.debian.org/experimental/python3).
In this status hplip is not installable.
- Bug#946561: hplip: Not installable with python3 >=... Stefano F.
- Bug#946561: Bug #946561 Stefano Fabri
- Bug#946561: Bug #946561 Didier 'OdyX' Raboud
- Bug#946561: Bug #946561 Stefano F.
- Bug#946561: Bug #946561 Brian Potkin
