How do I change Apple Account region to manage restrictions?

The support article Change your Apple Account country or region - Apple Support describes how to change your country setting on everything using your Apple Account, and the requirements and results of doing this.

It may be helpful to see a screenshot of the message you are seeing as there are many forms of Locks, Restrictions or Disabled messages that you may see. This may help getting you started in the meantime.

If your Apple Account is locked, not active, or disabled - Apple Support

Many Restriction messages are due to Screen Time settings or Apple Cash accounts. The Apple Cash accounts will be restricted when the information provided does not much what is available on your financial accounts. Banks consider this fraud and also Apple Cash is only available in the US so not even sure if that applies in your case.

Yep that is the Disabled message, not anything to do with the restriction messages that may be seen. The details on that message are at the bottom of the Support Article linked previously.

If your Apple Account is locked, not active, or disabled - Apple Support

Describe what happens when you follow those steps to reactivate the account or from the Continue option in the message.