Depends how you made the bottle. If you made it all with hot water put it in the fridge then reheat it. If it’s made hot shot/prep machine use within 2 hours
You can keep it in the fridge for 24h, but never use the microwave as it doesn't heat it through the same so you might have very hot patches without realising
If baby hasn't touched it, it can be refrigerated for up to 24 hours.
It can be cooled and put in the fridge then reheated. Microwave is fine as long as you make sure there’s no hot spots 😁
2hrs at room temp, 24hrs in the fridge (let it cool first) and then warm it up under the hot tap - don’t microwave :)