What kind of formula is good for 1 month plus baby as I tried Similac AR my kid doesn't like

You can try Nestle NAN optipro or Nestle NAN optipro H.A. My baby likes this. However, you can only trial and error to see which milk your baby likes. What other babies like might not be what your baby likes.

all formula milk brands are good just have to trial and error. hopefully your baby prefers budget brands and not the expensive ones

my babies have tried various brands but mostly dumex value-for-money

my LO is currently drinking Enfamil Gentlease