Scribus
Also on WindowsDesktop publishing for flyers, newsletters and brochures.
Installs from Ubuntu's own software archive.
Looking for InDesign on Linux? Scribus does the same job for free, and TuxPick installs it for you.
Install Scribus with TuxPickIt works on Ubuntu 22.04 and 24.04, and on systems built on them like Zorin OS and Pop!_OS.