Hello, I have been using Gammu successfully for several months on my Rasbperry pi 4 under buster.
I managed without problem to install Gammu on an SD with Bullseye 32 bits.
But impossible to install Gammu with Bullseye 64 bits:
during the order :
pi@raspberrypi:/tmp $ sudo apt-get install gammu libgammu-dev
Reading package lists... Done
Building the dependency tree... Done
Reading status information... Done
E: Unable to find gammu package
E: Unable to find package libgammu-dev

I tried :
sudo pip3 install python-gammu
but I have lots of error messages with this one at the end of the installation attempt:

ERROR: Could not find a version that satisfies the python-gammu requirement
ERROR: No matching distribution found for python-gammu

How to remedy this impossibility to install Gammu under bullseye 64 bits?
THANKS
PS: I'm French, I hope google traductino didn't make too many mistakes.

For the version of Bulleseye this is the version:
Raspberry Pi OS with desktop
Release date: February 21st 2023
System: 64-bit
Kernel version: 5.15
Debian version: 11 (bullseye)
thanks again