Latitude 5480 not detecting external display

I am trying to connect Dell Latitude 5480 to LG 4k Ultrafine display. Laptop does not have Thunderbolt. Display has only Thunderbolt and usb-c ports. At work I connect it via usb-c over DP port through WD15. I tried usb-c and HDMI but display has not been detected (display is not faulty as I was able to easily connect with my macbook pro). Do I have to use WD15 in order to connect Latitude with LG display? What port should I use between WD15 and dicplay?