
Hi LYVIV
Thanks for using Microsoft products and posting in the community.
I realize that you've encountered a problem.
Before I answer your question, I need to know some information to better help you with your problem.
Can you provide the exact error report? There are different solutions for different error reports.
Are you trying to share Microsoft 365 to your child's email address via email sharing?
If you are trying to share Microsoft 365 Family to your child's email, here is the official link that will tell you how to do it:
Share your Microsoft 365 Family subscription - Microsoft Support
Due to the limited information you have provided, I am unable to give a more detailed solution. ****
I hope you can let me know exactly what the problem is, what software you are using to share, and what device you are using.
Best regards.
Petter.Y - MSFT | Microsoft Community Support Specialist