Sure you can, only keep in mind that the online schools are expensive. The cheapest you'll find is about $225/month.
- Read about online high schools here: https://covcell.com/finishing-high-school-online-possible/
- You can read about high schools for adults here: https://covcell.com/high-school-diploma-adults/
- Alternatively, you can attend GED, HiSET, or TASC prep classes and get your High School Equivalency diploma.