Yes, this TV supports HDMI 2.1, but since it is a Samsung TV, Dolby Vision is not supported (no Samsung TV supports Dolby Vision), here are the detailed specifications of the HDMI interface:

HDMI 2.1 Features
4K@120 Hz, VRR (Variable Refresh Rate), Dynamic Metadata (HDR10+), ALLM (Auto Game Mode), eARC (on HDMI port 3).