Ubuntu:

sudo apt install perl perl-tk
[download]

You could also install your own Perl using perlbrew. This is great if you're in a shared environment, if you better control over the versions of Perl and modules, or if you want to install modules which aren't provided by your system's package manager.

curl -L https://install.perlbrew.pl | bash
perlbrew install 5.40.0
cpan Tk
[download]

Don't forget to add to your shell's startup script as directed.

As far as I know both have Perl installed by default. There are ways to install different versions of Perl on MacOS and switch between them but that is another matter.

Open the terminal and enter,

perl -v
[download]

Ubuntu 24.04 aka Noble Numbat has Perl version 5.38.2 installed by default. There are some modules in place already, but when you add more it pays to make every effort to get the modules from the official repositories before turning to CPAN itself.

As for MacOS, I have not used that for years but homebrew would be the way to add any missing modules before turning to raw CPAN.