Loading v4l2loopback kernel module

[Stefan Baums <baums@stefanbaums.com>]

Dear list,

I installed the v4l2loopback-linux-module package, but the module
was not loaded. Next I added the following to my system.scm:

   (services
     (append
      (list

      ...

            (simple-service 'my-kernel-module-loader-v4l2loopback
                            kernel-module-loader-service-type
                            '("v4l2loopback"))
      ...

   )
      %desktop-services))

and reconfigured, but the module was still not loaded. Even manual

   sudo modprobe v4l2loopback

fails with

   modprobe: FATAL: Module v4l2loopback not found in directory /run/booted-system/kernel/lib/modules/5.17.1

What am I supposed to do?

All best,
Stefan