404 Not Found [IP: 80] - Connection error while installing via homebridge

I am a new user to homebridge and had procured the ConbeeII stick and was trying to install it through homebridge by going into sudo hb-config menu options.

While the process does complete, upon returning to the terminal I noticed the below -

Hit:1 http://raspbian.raspberrypi.org/raspbian bullseye InRelease
Ign:2 http://phoscon.de/apt/deconz bullseye InRelease
Hit:3 http://archive.raspberrypi.org/debian bullseye InRelease
Err:4 http://phoscon.de/apt/deconz bullseye Release
**404  Not Found [IP: 80]**
Reading package lists... Done
**E: The repository 'http://phoscon.de/apt/deconz bullseye Release' does not have a Release file.**
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.## Steps to reproduce the behavior

could someone please help in getting this resolved?

Additionally, the web GUI for adding devices to phoscon at port 4530 does not load.

I tried all solutions that was reported for similar issue (inclg. changing the line in /etc/apt/sources.list.d/deconz.list to “deb [arch=amd64] http://phoscon.de/apt/deconz bionic-beta main”

  • Host system: (Raspberry Pi)
  • Running method: (Homebridge)
  • Device: (ConBee II)
  • Do you use an USB extension cable: (yes)
  • Is there any other USB or serial devices connected to the host system? (No)
  • USB port connected to (USB 2.0)

The device has been identified correctly as per the following logs -
pi@homebridge:/var/lib/homebridge $ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 1cf1:0030 Dresden Elektronik ZigBee gateway [ConBee II]
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
pi@homebridge:/var/lib/homebridge $ ls -l /dev/ttyA*
crw-rw---- 1 root dialout 166, 0 Nov 21 19:14 /dev/ttyACM0

The deCONZ version for Bullseye is only available in beta repository for now. The servers are up.

Please follow step 3 (Beta alternative) from here: