Looking for advice on transition to formula

Looking for advice transitioning our 9 mo baby girl to formula. Up until this point she has been exclusively breastfed, she will take a bottle and usually has 1-2 a day fed to her by her dad.

We introduced Kendamil two weeks ago, initially she took two bottles two days in a row no problem and then started rejecting it. After that we went back to breastmilk bottles and then 75:25 breastmilk:formula. She accepted 60:40 once and then today is rejecting that. Do we switch brands? Do we go back to 75:25 for longer? Has anyone experienced issues where as soon as baby notices the taste of the formula they reject and if so how did you get through that.

Open to any advice on how to make this transition easier, I return to work in September which requires me to travel so ideally would like to be fully weaned by then. Thank you!!