Get the adapter with USB output in addition to the HDMI output. You can also get the one with charge input like this https://www.amazon.com/gp/product/B07DL29W4X/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

I got this one, waiting to test. For fun I tried it with my GF's S8 and it does screen mirroring but no DeX as was expected. I wanted one that had charging ability.