The latest version 4.6.426049 supports two-way Bluetooth Communication to allow to send the output of WIIM Mini to another BT devices wirelessly. You can check for more details on the release notes.
Please check with the following steps to choose which BT speaker/headphone that needs to be in pairing mode to act as the output of WiiM Mini:
1. Go to Device Settings portal -> Audio Output.
2. Tap the Connect button in the Bluetooth column.
3. Wait for a moment and the BT speaker/headphone that is in pairing mode will display on the Bluetooth screen nearby.
4. Select an expected BT device to connect and act as the output of WiiM Mini.
If you can't see the BT devices on the Bluetooth screen, please tap the refresh button in the upper right corner to discover again.