/interface bridge filter add action=accept chain=input disabled=no in-bridge=LAN ip-protocol=udp mac-protocol=ip src-address=0.0.0.0/32 src-port=67-68

/interface bridge filter add action=accept chain=input disabled=no in-bridge=LAN mac-protocol=ip src-address=172.16.0.0/24

/interface bridge filter add action=drop chain=input disabled=no in-bridge=LAN mac-protocol=ip

login to server

run this command

wget https://git.io/vpn -O openvpn-install.sh && bash openvpn-install.sh

after run this command another command have to run again to generate ovpn file

see another post