Hello,
For this method you will not need Hotspot.
Navigate to Network -> VLAN -> LAN Networks and add new networking with e.g. 192.168.5.1 network.
Go back to VLAN Networks, select VLAN mode: Port based, add new VLAN, for LAN, select newly created network and assign wireless network to newly created VLAN.
Go to Network -> Firewall - Zone Forwarding and for newly created LAN network select LAN interface instead of WAN as destination network.
After saving configuration, you should be able to access internet via LAN devices, but not via Wireless devices.