Extract lldap's FreeBSD tar.gz under /usr/local/:
tar -xvf x86_64-freebsd_lldap-0.5.1.tar.gz -C /usr/local/
Move rc.d script into the right place:
mv /usr/local/lldap_server/rc.d_lldap /usr/local/etc/rc.d/lldap
Make your config, if your want to enable LDAPS, copy your server key and certification files, and set the owneship (currently www):
cp /usr/local/lldap_server/lldap_config.docker_template.toml /usr/local/lldap_server/lldap_config..toml
Enable lldap service in /etc/rc.conf:
sysrc lldap_enable="YES"
Start your service:
service lldap start