OK - then, yes, you can put your baby to the breast and see what happens
The only really effective way to increase your supply is to remove milk from your breasts as often as possible - this is what drives the supply. In your case, you will be helped by expressing at least 6-8 times in 24 hours, inc at night (which is pretty demanding), and by putting your baby to the breast and feeding her. She may co-operate, or she may not...difficult to predict. Even if she does, you will need to build up your supply rather than simply dropping the formula ... you can give her the expressed breastmilk, of course
Does this help? If you search relactation on here and on the web you'll get more info.