How do you say 'where are you?' in Japanese?

Question:

me and my friend haven't talked in awhile and to I want to say 'where are you? I really miss you so much.' I know 'I really miss you so much is: 私はあなたがいなくて本当にすごく寂しい
わたしはあなたがいなくてほんとうにすごくさびしい (correct if i'm wrong) but how do you say 'where are you?' like looking for you???

Answer:

>'where are you?
今どこにいるの？
ima dokoni iruno?

This includes "ima" which means "now". But it's customary to say it when you say "where are you?" in Japanese.