I have a Tile Pro 2018 in my car that is registered in the Beacon - An app for presence detection using BLE beacons (2020 version is not supported) app. That way I can see if my car is there. You should hide it though, in case some one leaves the beacon and takes the bike.
Putting a smart doorbell with a camera there will also work preventive I think. You can also put an alarm on people detection at night.
