I’m actually trying to connect my TV. Best Buy basics usbc to hdmi cable worked. All these hub multi function usb c to hdmi claim 4k at 120 but I suspect it’s a lie and the only one that worked was the one with no other connections. 12.99 at Best Buy 
I've got a hand full of supposed HDMI 2.1 USB adapters. None of them seem to let me do 4k more than 30HZ.   I understand there is a limitation on the USB for data throughput. Should I get a USB to DP? Will that give me what I need? 
XPS 9380 4k @ 60HZ external monitor