This looks like a broken, or at least inconsistent installation.

Examine the file /usr/opt/perl5/lib/site_perl/5.28.1/CGI.pm: Your code seems to assume that this is the library CGI, but this library definitely does not call CGI->new.

Perhaps you can track down where this CGI.pm comes from, and how /usr/opt/perl5/lib/site_perl/5.28.1/ ended up in your @INC directory. Or you could try installing CGI.pm with the package manager of your distribution, or from CPAN, and make sure that this version is used instead of your weird one.

Also, cgi-lib seems to be something from a very distant past.... where did that script come from? Perl 4?