To buy an app from the Windows Store in a specific country or region, you need to change the location for your PC and then add a payment method from that country or region to your Store account. For example, if you buy an app from the Store and your PC's location is set to the United Kingdom, your payment method needs to be one from the United Kingdom.
Swipe in from the right edge of the screen, then tap Search.(If you're using a mouse, point to the bottom-right corner of the screen, move the mouse pointer up, then click Search.)
In the search box, enter region, then, in the results, tap or click Change your country or region.
Select the country or region for your location from the list.
You might need to restart your PC for these changes to take effect.
On the Start screen, tap or click Store to open the Windows Store.
Swipe down from the top edge of the screen, then tap Your account. (If you're using a mouse, right-click, then click Your account.)
Tap or click Add payment method, edit any necessary info, then tap or click Submit.