Installation of PyQt6 fails on Ubuntu 20.04

[JakobDev]

The installation of PyQt6 fails on my Ubuntu Mate 20.04 System.

jakob at Pluto:~$ pip install PyQt6
Collecting PyQt6
   Downloading PyQt6-6.2.1-cp36-abi3-manylinux1_x86_64.whl (7.7 MB)
      |████████████████████████████████| 7.7 MB 3.6 MB/s
Collecting PyQt6-sip<14,>=13.1
   Downloading PyQt6_sip-13.1.0-cp38-cp38-manylinux1_x86_64.whl (289 kB)
      |████████████████████████████████| 289 kB 3.2 MB/s
ERROR: Could not find a version that satisfies the requirement 
PyQt6-Qt6>=6.2.1 (from PyQt6) (from versions: none)
ERROR: No matching distribution found for PyQt6-Qt6>=6.2.1 (from PyQt6)
jakob at Pluto:~$

It can't install PyQt6-Qt6 for some reason.