You can carry out your activities wherever activities for young people are offered, not just at school. So also at a sports or youth club, at the music school or at a non-profit organisation, e.g. an animal shelter, the nature conservation association, the food bank or the homeless shelter.
Therefore, you can take part wherever activities for teenagers and young adults are offered and have this activity count towards your Award. The prerequisite here, of course, is that you do your activity at least for one hour per week.
But your activities don’t have to be organized. If you want to become an activist or a DJ, you can also acquire the knowledge yourself, for example through YouTube tutorials. All you have to do is document what you are doing and demonstrate that you have achieved your personal goal.