xxxxxx@xxxxxx:~$ sudo add-apt-repository ppa:freecad-maintainers/freecad-stable
^[[A^[[A^[[B^[[B^[[B^[[BRepository: 'deb https://ppa.launchpadcontent.net/freecad-maintainers/freecad-stable/ubuntu/ bookworm main'
Description:
This PPA repository hosts stable releases of FreeCAD for all supported versions of Ubuntu in 32 and 64-Bit architecture. These packages are more up to date than those found on the Ubuntu repositories.

Note: the freecad-doc package brings offline FreeCAD help support, and needs to be installed separately..

Note: the ccx package brings CalculiX support to the FEM workbench, and needs to be installed separately.
More info: https://launchpad.net/~freecad-maintainers/+archive/ubuntu/freecad-stable
Adding repository.
Press [ENTER] to conti
Adding deb entry to /etc/apt/sources.list.d/freecad-maintainers-ubuntu-freecad-stable-bookworm.list
Adding disabled deb-src entry to /etc/apt/sources.list.d/freecad-maintainers-ubuntu-freecad-stable-bookworm.list
Adding key to /etc/apt/trusted.gpg.d/freecad-maintainers-ubuntu-freecad-stable.gpg with fingerprint 9F0E375806520BD65BC61B18A728AE60A790F0EB
Hit:1 https://deb.debian.org/debian bookworm InRelease
Hit:2 https://deb.debian.org/debian bookworm-updates InRelease
Hit:3 https://ocean.surfshark.com/debian stretch InRelease
Hit:4 https://dl.google.com/linux/chrome/deb stable InRelease
Ign:5 https://ppa.launchpadcontent.net/freecad-maintainers/freecad-stable/ubuntu bookworm InRelease
Err:6 https://ppa.launchpadcontent.net/freecad-maintainers/freecad-stable/ubuntu bookworm Release
  404  Not Found [IP: 2620:2d:4000:1::81 443]
Reading package lists... Done
E: The repository 'https://ppa.launchpadcontent.net/freecad-maintainers/freecad-stable/ubuntu bookworm Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.