The method I have used in the past is to create a dummy entry in the known_devices.yaml file. There has been a warning about known_devices being phased out since v. 0.94, but it’s still working as of 2022.09…
#known_devices.yaml
my_manual_device_tracker:
name: Manual Device Tracker
icon: mdi:cellphone
track: true
The service to set the location would be something like:
service: device_tracker.see
data:
location_name: home
dev_id: my_manual_device_tracker