This is a great platform for quick daily posts to show off your work. However, it not as affective at Tiktok or Facebook with client reach.
I only use Snapchat to see videos of my grandchildren and family videos
Snapchat works well as a social platform for people in high school or college. However It is not advertising friendly for small businesses.
If your audience is there I would suggest that you create some great, creative and fun content there. Snapchat gives you the ability to talk about important causes without being too formal. People will love the creativity and they will be more willing to follow / help your non-profit. Snapchat is excellent for account takeovers: maybe let one of your biggest fans post for 24 hours talking about how much he / she loves your non-profit, for instance
This all depends on the type of business, your audience and the platform they are on.