Hello,actually when Iam changing the country in app store after the details given the next button is not working

Hi Cm0078,

Thank you for using the Apple Support Communities! If you are unable to change your country or region for your Apple ID, the guidance below can help:

Change your Apple ID country or region

If you can't change your country or region

* If you can't change your country or region, make sure that you canceled your subscriptions and spent your store credit. Complete these steps before you try to change your country or region.

* If you're a part of a Family Sharing group, you might not be able to change your country or region. Learn how to leave a Family Sharing group.

* If you still can't change your country or region, or you have less store credit than the cost of a single item, contact Apple Support.

Hope this helps!

Have a great day.