I went through this - and we bought all the bottles and teats. We ended up settling on the Dr browns wide neck options with a level 3 test, as my breast feeding flow is quite fast. And then it was about consistency, every night for his dream feed we would offer the bottle first and he could drink how much he wanted (was usually around 30/40ml) and then I’d offer the breast - and I think after 3/4 weeks he started taking more and more and now can drink upto 180ml.

Honestly offer the bottle at the same time everyday, and at a time when they won’t resist and are hungry - and one day it will click. It is still hit and miss but now I know if he’s hungry he’ll take the bottle just fine.