I have device_tracker sensor (created by ASUSWRT integration).
I try create binary sensor based on these sensors, but without success
I have (in configuration yaml):
There could be many reasons it doesn’t work. Depends on here you put that in configuration.yaml.
EDIT: after rereading your initial post and assuming you put that in the correct spot in configuration.yaml, the issue is that you chose to reload yaml instead of restart. Whenver you add a new integration via yaml, you have to restart. After that, adding new sensors (or making changes) can be achieved by reloading.