I tried installing the module using ppm, but ppm doesn't exist.

Yuup , http://code.activestate.com/ppm/CGI/ says

Notice! PPM is being replaced with the ActiveState Platform, which enhances PPM’s build and deploy capabilities. Create your free Platform account to download ActivePerl or customize Perl with the packages you require and get automatic updates.

There are no packages listed for perls higher than Perl 5.24

Although, platform.activestate.com...ActivePerl-5.28/customize does allow you to add a ppm package... but

Dang, unable to build! We were unable to build the distributions for this project because... No version of language/perl Compress-Raw-Zlib satisfies dependency language/perl Compress::Raw::Zlib >= 2.92 (of requirement language/perl ActiveState-Utils == 2.11), requirement language/perl Compress-Raw-Zlib == 2.7.6

Whatever