,,,Last I checked, telephone numbers, emails, and many, many, many other forms of social media still include. Ask if she's got Discord or Facetime or some other means of getting in touch.

Also, one hour is... really not that much. If you're in North America, odds are good at some point you'll be studying to get a driving license. It's not the end of the world.

"By the way, you mind if I can have your phone number/email/Discord username/social media username of choice so we can stay in touch?"

I get teenage hormones tend to make stuff like that seem way worse than it really is, but still. It's not the end of the world, and it doesn't need to be the end of your friendship, either. Just ask nicely.