Help with a girl

Ive known this girl for around 6-7 months, normally whenever i see her its always busy and in public, she is quite a shy girl. I have managed to catch her alone sometimes when it hasn't been so busy and had a few convos with her. I can never seem to have a good level of convo with her as she is shy and it is quite busy all the time. Recently I can never seem to get her alone privately and I really want to ask her for her social media. Next time I see her shall I just go up to her regardless of how busy it is and just ask her or wait till shes alone?

Where are you seeing her and what is she doing when you say "it's busy"?

yeah, ask her even if it is busy. bring it up casually. Like “hey I like talking to you, do you have social media?”

Its always busy on the bus

So if you see her on the bus, when would you try to see her 'privately'?