For "uname -m" is x86_64.
For "lsb_release -a" is the info of te Debian 11
You are trying to install rbfeeder on a computer with architecture
x86_64. Seems you have installed Raspberry Pi Desktop for PC and Mac (which is Debian 11) on a Laptop or Desktop. Please see screenshot attached below.
Unfortunately Radarbox24 does
NOT provide their feeder package for this architecture (x86_64). Their packages are available only for
armhf and
arm64 i.e. for Raspberry Pi or similar.