Yep! Just slowly transition to not hurt their bellies. But I couldn't produce enough for both of my twins after a month or two old, so then I supplemented whatever i didn't make that session with formula! Then when I was over it at 6m pp I slowly added an ounce more, every few days, of formula until it was the full bottles. Same with transitioning to whole milk. I started at 11m, 1oz whole milk to 3 Oz formula, the next week 2oz whole milk 2oz formula, the next week 3oz whole milk 1oz formula, and by their birthday they were fully transitioned to whole milk with zero tummy issues or fits
Do it gradually one feeding at a time. I wasn’t producing enough milk so giving my baby a full 8 oz formula bottle before bed was super helpful in relation to sleep.
Go slow and replace like 1 once of breast milk with formula until she or he is used to it. So if he or she eat 4 oz every 3 or 2 hr take 1 ounce of formula and mix 3 once of breast milk to make 4, and always do the formula first than add breast milk to formula than just keep adding more formula and less breast milk slowly