The M2 MacBook Air only supports one external display.
Macs do not support DisplayPort MST daisy-chaining or the equivalent. As a rule, Macs that can drive multiple external displays over USB-C or Thunderbolt support connecting
- One display to a USB-C dock
- Up to two displays to a Thunderbolt dock
Targus – USB-C Universal DV4K Docking Station with 100W Power Delivery
This does not look like a Thunderbolt dock to me. The description says "USB-A and USB-C, DP Alt. Mode, TB3 Compatible," but lots of vendors who make peripherals that depend on USB and DisplayPort Alt Mode will make claims that their devices are Thunderbolt-compatible.
So
- Your Mac only supports one external display.
- This monitor supports two external displays in some way (DIsplayPort MST daisy-chaining, or a "workaround" technology like DisplayLink) that would not work, without drivers, even on a more capable Mac.
- If you review the dock manual, you will very likely find that you are supposed to install a special driver on your Mac. Workarounds depend on the combination of a "magic decoder ring" chip set in an external adapter/hub, and a matching driver on the host computer. Neither the device alone nor the driver alone are enough.
- If you can get things to work, you may find that the arrangement comes with some compromises.