Here's a guide on how to switch to a US store on Android.
Log into your Google account on payments.google.com.
Tap "Add a payment method" and enter your card details, ensuring you enter the details as seen on your card.
If you previously had a card on Google Payment, you have to change your region and address before adding the Grey USD card. Go to the sidebar, tap settings, and change your country/region.
After changing your country/region, you can now add your Grey USD card for payments.
Yay!! You can now make payments on Android with Google Pay using your Grey Virtual USD card.
Declined Payment
If the payment fails after successfully adding your card, this is likely due to insufficient funds. Please ensure your card is funded enough to pay for all your subscriptions.