Flow monitoring on Grundfoss magna1?

Hi,
I’ve recently received an emonpi solar PV kit and emon tx, plus 4x CTs, and a optical pulse counter.
I plan to set these up to monitor our solar eenergy production and energy usage in total, and energy usage from the heat pump alone.
Reading a bit mmore info on the guide for setting up monitoring heat pumps, it mentions monitoring water flow to help measure the COP.
Anyone know what is the best and easiest way to measure water flow from the pump for our central heating system. The pump is a Grundfoss magna1 model C (see photo). There is an LED display on the pump which shows flows but I’m not sure how I could log this with the OEM hardware.

Good discussion about flow metering here: What is the best flow meter?

Thanks for link. I was hoping to avoid any plumbing and there would be a nice easy way to get flow rates direct from the pump via an electrical output. Doesn’t look like the pump I have can do that.