Needs a question mark, or the translation bedomes " a few minutes"
It's not a full sentence I don't think, and you could say "how many minutes" in a non interrogative sentence. "He wants to know how many minutes it takes."
but it's still a question, you literally cannot use an interrogative word such as how or 몇 without a question mark
"몇 분" means "a few minutes"
A few minuetes
"Several minutes." if there is no question mark...