To set your billing address:

1. Log in to your account.
2. Click on "Account Setting" and select "Billing Details".
3. Click "+ Add new billing address" button.
4. Enter your full name, address, city, state, zip code, country, and phone number.
5. Click "Save" button.
6. This new address will now show up as an option when you check out.
7. Select it as your desired billing address.