Try again.
You automatically get a girls number if she really wants to give it to you.
Not something you need to ask for.
I've had nights out with buddies though where we see who can get the most numbers as a joke and a couple of us have about 10 different ones in our phones. Only about half will text back. Leaving the bar/party with an attractive girl and getting invited back to her place is the ONLY thing a man should be proud of. Getting phone numbers doesn't don't count.
Asking a girl you recently met your place or mine takes balls and when done right is the boss line to drop.