How to pass jquery object into imgcheckbox jquery plugin?

i found a jquery plugin to change our img tag into a checkbox You can see it here:

http://ift.tt/2jELStI

As i read in the documentation, we can pass jqeury object instead of form element to the addToForm option, to avoid using form tag.

Anyone can explain to me how we pass jquery object into that option?

I prefer not to use form tag.

Thanks before...

Here is the image of the documentation