My son doesn't want to drink water. His already 3 years old. What should I do.

Pero nakakainom siya ng milk? Baka ayaw niya dun sa lagayan ng tubig baka type niya naka straw mi gawan mo paraan iba ibahin mo type ng tumbler o baso niya Possible kasi madehydrate siya at masweruhan kung kulang sa fluids.. Kung 2weeks no water pacheckup mo mii