[Kwant] Dangling bonds

Hello everyone, I would appreciate any suggestion you could give me to solve this: Im currently working on a 2D finite monolayer of certain material that is coupled to a pair of leads in both left and right sides, the thing is: how can I get rid of the dangling bonds that appears in the edges of the nanoribbon?, I cant use the function "eradicate dangling" because the dissapearing atoms will just generate new dangling bonds. (By the way: I tried to use this function just to see what happens but nothing changed in the structure, is that normal?) So, Is there a way to automatically fill the dangling bonds with Hydrogen atoms? Or do I have to do it manually? Thanks in advance.