$ which perl
/home/ken/perl5/perlbrew/perls/perl-5.36.0/bin/perl

$ perlbrew list
 * perl-5.36.0
   perl-5.34.0
   perl-5.33.5
   perl-5.32.0
   perl-5.30.0

$ perlbrew switch perl-5.30.0

$ which perl
/home/ken/perl5/perlbrew/perls/perl-5.30.0/bin/perl

$ perlbrew switch perl-5.36.0

$ which perl
/home/ken/perl5/perlbrew/perls/perl-5.36.0/bin/perl