/usr/share/man/man8/tsig-keygen.8.gz is in bind9 1:9.10.3.dfsg.P4-8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man8/ddns-confgen.8.gz
/usr/share/man/man8/ddns-confgen.8.gz