Connecting a dual-sided TWiN2 power meter looks identical to a single-sided one.
ANT+ connection: In your computer go to settings / sensors / add new. Then search for available devices and select the one ANT+ ID that corresponds to your power meter .
BLE connection: In your computer go to settings / sensors / add new. Then search for available devices and select the device named POWERCRANK L.XXXX (where XXXX is the ANT+ ID digits that corresponds to your power meter).