How to connect two Dell UltraSharp U2412M monitors to the new XPS 15?

[Windows Central Question]

My monitors have DisplayPort but not HDMI.

I've read so many articles about USB-C, HDMI, Thunderbolt, mini DisplayPort, DisplayPort etc, but still have no clue what actual product I would need to buy to make my DisplayPort-only Dell UltraSharp U2412M monitors connect to a new XPS 15.

I want them to add extra screens, not copy the laptop screen, so that I get three screens in total.