CGAL library package missing in ubuntu 20.04

according to https://doc.cgal.org/latest/Manual/installation.html

Since CGAL version 5.0, CGAL is header-only be default, which means that there is no need to compile CGAL or its libraries before it can be used.

Are you sure that you need that package?

Thank you for your fast answer.
In fact, I need to compile a software built with CGAL 4.9.1.
In Ubuntu 19.10, the CGAL version was 4.9.14, and curiously, the compilation fails.
I found a workaround by using the header files of CGAL 4.9.14 and the libraries of Ubuntu distribution (corresponding to CGAL 4.9.14)
The compilation fails if I am using CGAL 5.0 and my workaround fails because the compiler requires the CGAL library.

Either I need to patch the CGAL part of the software (unfortunately, the CGAL documentation is not easy to to use) or to compile
the old version of CGAL.

It is a weakness of the software that you want to build, if it requires a specific (and outdated) version of CGAL.
I do not see any possibility for Ubuntu to help. You probably better try asking where that software comes from. Maybe they know how to compile it with a version of CGAL higher than 4.9.1, especially with 5.*

Remark: CGAL 4.9.1. was provided three years ago in Ubuntu zesty and artful, both already in "end of life" status.

I think that the issue comes from the software and not ubuntu.