Where to place {JFBCLogin} tag in CB login module

I honestly don't know their module code off the top of my head, and Community Builder code, in general, can be extremely hard to read. Also, you didn't really say where you wanted it.

One thing we'd recommend as a possibility is simply creating a Custom HTML module, set it to the same module position as your CB module, set the ordering to below the CB module, and disable the Show Title setting. Then, in the HTML box, simply put {JFBCLogin}. This will display the Login With Facebook button directly below the CB module, and may be exactly what you're looking for. It also allows you to easily add a little text like "Or login with Facebook below!". However, depending on your template, this doesn't always look perfect.

Hope this helps, but if you need more help, let us know, and specifically, where you'd want the button in the module. We can look into the code, but it may take a little while to get a good answer for you.

Good luck!