assuming you have the software/cli try
nmap -sU -p 9898 192.168.1.199
and
nmap -sU -p 4321 192.168.1.199
Both ports need to be open for the LAN access to the hub to work - see https://community.home-assistant.io/t/cannot-connect-xiaomi-gateway-lumi-gateway-v3-to-ha for more.