Hello Frédéric
This may be a bit off topic...
Installed successfully HamPi_v3.0.1_64bit.img.xz on RPi4B. I was driven by curiosity rather than necessity. WSJT-X and JTDX compiles/installs O.K.
Installation of HamPi is exactly the same like for other RPi images. No tricks needed.
From my point of view HamPi is full of various stuff. Myself I prefer to install only programs that I need.
Therefore 2022-04-04-raspios-bullseye-arm64.img.xz is perfectly O.K. or 2022-04-04-raspios-bullseye-armhf-full.img.xz
In case of uncertainty which version to install see here: https://symless.com/synergy-help/do-i-install-armhf-or-arm64-on-my-raspberry... Short answer: 64bit processor, install arm64 OS.
I do have SDR radio which is not supported by RPi and therefore I can't check RPi4B in action, Hi!
However YMMV...
Best regards.