Wearing off formula

Since our babies are so close to a year old I’m just wondering how y’all are going to transition off of formula/breastmilk. Last night Olivia refused to eat her bottle for dinner. She just wanted some of my pizza and a pouch. I didn’t force the bottle and gave her what I was eating and she ate it all. First time mom and plan on asking her peds but just wanted to see what others are doing as well. We are also on a high cal formula bc she is a slow weight gainer. She just reached the growth chart for 3rd% in weight she I don’t even know if my peds will let me come off at 1 year.