Hi JoyLopez2017!
I understand you'd like to turn off Ask to Buy on a Family Sharing account, and I'm happy to help. Here are instructions:
The family organizer can turn on Ask to Buy for any family member who isn't an adult. It's on by default for any children under 13, and you'll be asked to set up Ask to Buy when inviting anyone under 18 to your family group.*
Use these steps to turn Ask to Buy on or off for family members who are under 18* in your family group. If you turn off Ask to Buy for a family member after they turn 18,* you can't turn it on again.
- Go to Settings > [your name] and tap Family Sharing. If you're using iOS 10.2 or earlier, go to Settings > iCloud and tap Family.
- Tap your family member's name.
- Tap Ask to Buy.
- Choose Apple menu > System Preferences > iCloud.
- Click Manage Family and select your family member's name.
- Select Ask to Buy.
If you created your child's account using Apple ID for Students, you can use Ask to Buy for personal purchases outside of the educational institution. It won't apply to any apps or other content distributed by the school.
Request and make purchases with Ask to Buy
Thanks for using Apple Support Communities.
Cheers!