Extras - Switch for Fallback Internet not available/showing
**Describe the bug**
I have successfully configured the plugin, allowing me to get switches for Fritzbox on/off, LED and reconnect besides others. All works as expected, switches appear in the Home app and also work.
However, when tryiing to configure the Option->Extras->Fallback Internet and select it to be a switch and corresponding states for on and off, such a switch NEVER shows up anywhere in homekit or the home app. I also tried different apps (Eve) to no avail.

**To Reproduce**
Homebidge config extract:
"extras": {
                "fallbackInternet": {
                    "active": true,
                    "provider": "DEUTSCHE TELEKOM",
                    "onState": "1",
                    "offState": "3",
                    "accType": "switch"

I tried various other values for on/off state (0,2) with no change, it just does not work for me, no switch is shown/coming up.

**Expected behavior**
A switch to be able to turn fallback internet on/off should be aviailable in the home app or homebridge.

**AVM Device**
 - Fritz OS 7.50, Fritzbox 6591

-Homebridge: 1.6.0, Node.js: 18.14.2


**Additional context**
When making this Extras option a characteristic, I am able to get info on fallback internet status shown, but is read only.
