The dock will support up to 2 Displays Max. 

HDMI #1 + HDMI #2 or HDMI #1 and DisplayPort (HDMI port farthest from the DisplayPort)

Please note: Dual display is only supported on Apple M1/M2 Pro and Max, Intel-based MacBooks, and compatible Windows devices. (like the Surface Studio Laptop) 

It will only support 1 external display when using an M1 or M2 MacBook Pro/Air

This is not a limitation of the Dock, but a limitation of the Thunderbolt 3 / USB4 ports on the new M1/M2-based Macs