Testing GLOW sensor

Does anyone have a reliable method of testing the glow sensor / pulse meter?

My electric meter is outside, and currently all the components are a bit jumbled together, so would rather the ability to confirm that it’s able to at least read the pulses before attaching it to the electric meter.

I guess in theory i just need to create a flashing red LED.

A well lit room (use a desk lamp) and covering the sensor with your finger then uncovering it momentarily should work too.