I have done a bit of research on this. However i did not follow through to the end because I went a different route (my meter sends radio signals I went with This )
If your meter has a visible to the naked eye blinking light then any Photoresistor well work.
Some basic hookup info Here and I think you would use a Binary Sensor component to read the blinks.
Something like that.
Sorry for the brief description, like I mentioned I did not follow through with this solution.
I hope it’s of help.
Edit: I found a link I had bookmarked for reference, that is related. It might be of help to you. https://forum.arduino.cc/index.php?topic=416054.0