/usr/lib/x86_64-linux-gnu/libduo.so.3 is in libduo3 1.9.21-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libduo.so.3.0.0
/usr/lib/x86_64-linux-gnu/libduo.so.3.0.0