I have a port replicator that will fit a Surface Laptop Go 1, 2 and 3 and the Surface Laptop 3.  It worked with my Surface Laptop Go and the only reason I am selling it isI spilt water over it and it died :-)

It looks like this

So it connects to the 3 ports on the laptop (USB 3.0, USB C and 3.5mm and provides Gigabit ethernet, 2 USB 3.0 ports, 4K HDMI, PD/Data and 3.5mm jack

$20 if you can pick up in Wellington, else add shipping.