At a minimum, eARC requires that both an audio device and its connected HDMI port support HDMI 2.1. If you're unsure, check your audio gear's specifications, and connect it to the port marked "eARC" ...
Using a technology known as ARC (or eARC, depending on your HDMI version) you can simplify cabling and unlock much greater support for uncompressed, lossless audio. That’s not the best solution ...