As per https://www.phpbb.com/community/viewtopic.php?f=6&t=2365386 user https://www.phpbb.com/community/memberlist.php?mode=viewprofile&u=1543916 sent an e-mail to the address given at https://www.phpbb.com/about/contact/#else on the 13th of April 2016 23:43 and never got a reply.

Either nobody ever got the e-mail, or nobody ever responded. I created the ticket for him.