Catfish, I am assuming you have a male connector on the charger and female on your batteries. If so that would mean you esc has a male connector. If all of the above is true, that means on the meter you have a male connector on the source (input) side and a female on the load (output) side. So what you need to do is make two sets of wires.
One female to female
One male to male
The female to female goes between the charger and the (input side) of the meter
The male to male goes between the (output side) of the meter and the battery.

I would hope you have the female plug on the batteries. Also make sure when you wire and solder, always red to red black to black, so on and so on. BG