Bunnies Fighting! Help please

Hello I'm a new owner and I don't know how to bond bunnies. We have had Buttons for 2 weeks and then got Dots, but Buttons reacted poorly to Dots and I believe that they're trying to dominate one another. However when Dots turns her back Buttons goes for her butt! Buttons chased Dots all around the cage and she kept trying to get away from her. They circle each other and bit each other hard enough the make them scream a little. Our solution was to stick Dots in the cage and let Buttons circle and smell her and get used to her.

Help please! I'm open to any suggestions! Dots is 6 weeks and Buttons is around the same age. They're both female, but we aren't too sure on Button's gender.