XGIMI Elfin supports amplifier. You can do as follows to use amplifier by means of your XGIMI Elfin.
The projector offers two HDMI ports for external connection, which makes the screen mirroring much easier for any daily usage.
Please connect the external device to the HDMI ports of XGIMI Elfin, and follow the below system routine for further setup.
Then you can use amplifier of your XGIMI Elfin.