cannot create an apple ID for my kids

If the child is age 13 or over, see How to create a new Apple ID https://support.apple.com/en-us/HT204316.

For a younger child, you will need to set up family sharing. See

Family Sharing - Apple Support

Set up Family Sharing – Apple Support

Family Sharing and Apple ID for your child - Apple Support

Family Sharing and Apple ID for your child under 13 years https://support.apple.com/en-us/HT201084

contact Apple ID Support for assistance.  See the Apple Support articles below for contact information.  

Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.   (Link doesn’t always load)  

Get Support          Work through the screens to get a chat option. You may have to pick a slightly different problem.

Starting an online chat with Apple Support

Apple Support schedule phone call

https://twitter.com/AppleSupport.          People have posted it may take an hour or more to get a response.