start
fun startProximityPresentation(context: Context, timeouts: ProximityTimeouts = ProximityTimeouts(), modes: Set<ProximityBLEMode> = ProximityBLEMode.entries.toSet()): ProximityPresentation(source)
Starts an ISO/IEC 18013-5 in-person presentation over BLE: show its ProximityPresentation.qrCode. In modes, both by default, it advertises for a reader (peripheral server mode) and scans for one (central client mode) until a reader connects either way; a reader offered both should choose central client mode. It needs Bluetooth on and ProximityPermissions.holder for modes granted (ProximityException otherwise).