I have a network interface (usb0) that I wanted to share over WiFi, so I created a new connection, set it to AP and Shared and tried, if it would work. The first hurdle was having to install dnsmasq. The unsecured AP started working, but a secured AP still fails to work, how to make a secured AP work with key? Do I need to install additional apps?
You want to set yourself up as a wifi spot... if I understand and which has nothing to do with KDE or dnsmaque. It has to do with setting up the wifi and routing.
KDE does support setting up AP hotspots. I have one working, but without security, open to everyone. I know how to setup one without KDE, but don't want to bother. What I want is setting up a WiFi hotspot using KDE System Settings -> WiFi & Internet.