Gravity Lightning Sensor - software not working

Greetings

i have a Gravity Lightning Sensor and down loaded the software shown on the DFRboot website for a Raspberry Pi. The order of files shown is incorrect. I tried to use python 3.9 idle to run the Ordinary.py examaple program. I get an error message —“from DFRobot_AS3935 module not found error - no module named DFRobot_AS3935_lib 

not sure what to do?

please help

tom