just copy it anywhere where perl is looking ( @INC ).

No, place it here in the directory output by the following:

perl -V:installsitelib
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Or create "lib" directory next to your script and use lib "lib";

No, that won't always work before 5.26 (because it assumes the CWD is the script's directory), and it introduces a security vulnerability in setuid scripts. You want:

use FindBin qw( $RealBin );
use lib "$RealBin/lib";
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