This documentation applies only Turris OS 3.x that is no longer present in newly sold routers. The new documentation is located at https://docs.turris.cz/.
If you want to let guests use your Wi-Fi without giving them access to the entire network, then guest Wi-Fi might be exactly what you need. This simple setting in Foris enables a guest network, which is separate from the LAN network. Devices connected to this network are allowed to access the internet, but aren't allowed to access other devices and the configuration interface of the router.
To set up guest Wi-Fi, go to the Wi-Fi tab in the Foris user interface, simply check the option
Enable guest Wi-Fi and fill out the desired password. You can also change the name of the network from the default “Turris-guest”, if you want to be a little more creative. After that just click Save changes and you are all set.
Parameters of the guest network can be set in the LAN tab, where you can set the IP range for your guest network. This range should be different to the ranges on your other networks (LAN, WAN, VPN, etc.).