/usr/bin/start_webtool is in erlang-webtool 1:16.b.3-dfsg-1ubuntu2.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../lib/erlang/lib/webtool-0.8.9.2/priv/bin/start_webtool
/usr/bin/../lib/erlang/lib/webtool-0.8.9.2/priv/bin/start_webtool