From what I can see they need to actively provide a Perl engine at the back-end to run the code.

I quickly searched their discussion board and found 3 threads requesting Perl, alas without answer.

Like https://leetcode.com/discuss/feedback/1051600/Perl-support-wanted

So, I only see 3 options

• you convince many monks to join leetcode to petition in large numbers in the board.
• you start punishing their snobbish attitude, by "steeling" their questions to discuss them here on PM. (a win for the monastery)
• a combination of the former two

HTH! :)