I cant change my child's Apple Id

Hi SlyTroy,

Thank you for participating in the Apple Support Communities. We understand you're following the correct steps to change your Apple ID password on your iPhone, but it's not working. If you're connected to cellular data, we recommend trying a Wi-Fi connection, or vice versa. This can help rule out a network issue. Restarting your iPhone may help as well, as this can refresh iOS, apps and connections.

1. "Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo."

These steps are from this article: Restart your iPhone.

If that doesn't help, try changing your password on another device or using a web browser as explained in this article you are following: Change your Apple ID password.

We hope this helps.

Take care.

Thanks for the reply, SlyTroy.

It looks like the resource you mentioned was for an Apple ID password instead of changing an Apple ID. You'll find the steps to change the Apple ID here instead: Change your Apple ID - Apple Support

If you still need help with changing the Apple ID, Contact Apple Support directly for additional guidance.

All the best.