Question about TP-Link Deco M4 AC1200 Dualband WLAN Mesh 1-pack

I use a single Deco M4 to connect printers to Mac, iPad etc. (without internet connection). It actually works, but the network is unsecured. According to the manufacturer, WPA2 and WPA3 are available. But there is no security key on the product. Operating an unsecured network is completely unacceptable to me.