Scanning for Bluetooth devices requires the access to Location Services permission to be enabled. This is because a Bluetooth scan can be used to gather information about the location of the device through a signal strength for example. The PhocosLink App does not use, save, nor transmit any Location readings. This is not driven by Phocos but is an Android requirement for Bluetooth.
More official information about this can be found here: https://developer.android.com/guide/topics/connectivity/bluetooth