Ask-to-buy requests not showing up

If you miss an Ask to Buy notification, you can find the request in Notification Center on your iPhone, iPad, iPod touch, or Mac. If you still don't see your Ask to Buy requests, check which Apple ID you're signed in with, check your Family Sharing settings, and make sure that you're on a supported device.

If Ask to Buy isn't working - Apple Support (IN)

I have setup Ask to buy for an iphone for my 10 year old nephew. When he wants to download something, he sends the Ask-to-Buy but I am not getting the request. I am using a Samsung phone, android OS...