Yes, we can config netflow on MX to monitor traffic on PRTG. 😄
... but in my case the result is wrong parameters or numbers 😞
Meraki Dashboard: Enable netflow, enter PRTG IP (e.g: a.a.a.a) and netflow port (e.g: 2056) .
PRTG: create a sensor with Receive NetFlow Packets on UDP Port is 2056, sender IP is MX's IP, and time out is 5 mins.
If you have PRTG support, you can open a case and post the solution here.
Hope this help.
natuan