Gravity Heart Rate Monitor (ECG) Problems

Hi!
I am having problems regarding the Heart Rate Monitor (ECG) Sensor I have placed the sensors properly on my body, (The red one on the upper right, the yellow one on the upper left and the green one on the lower right). Now I can see on the board that the LED labeled as "Heart", "R", and "L" are lit up. I am wondering what does those mean?
I also uploaded the sample code 1 found here: https://www.dfrobot.com/wiki/index.php/ ... mple_Code1

but the result of the Serial plotter is not what I am expecting. (shown below) I have tried all the tips on how to get a good signal but still I haven't had a good signal.

I really need this sensor to work for my project. Any help would be greatly appreciated.