You measure the flow rate via the RPM, which is read out through the 3-pin connector. You can plug this into any fan header, whether it’s a 3-pin or a 4-pin PWM header—that’s up to you.
The 2-pin connector is for reading the temperature. You’ll need to check your motherboard manual to see if it offers a suitable header. If not, you’ll have to use an external controller. We don’t offer controllers, so you’ll need to do some searching online to see what options are available.