Girls, hello! Could you please tell me how you prepare this dill water…

Girls, hello! Could you please tell me how you prepare this dill water? My little one is 1.5 months old, and the instructions say to dilute it in boiled water (100ml), and below the instructions there's a warning that babies should only be given freshly prepared solution, and it says to give after feeding, but after feeding, 100ml of baby won't drink, will they? Even 50ml if I make it, he won't drink. And so all the un-drunk amount has to be poured away? And every time do a new batch?