If you've already placed an order, you won't be able to change your delivery address for that order. The seller can only ship to the address you input when the order was placed.
To change your delivery address for future orders, you'll need to:
- Visit your profile
- Tap the 3 lined icon in the top right of the screen
- Go to Settings > Delivery Addresses > Edit
- Type in your new address and click "Save Changes"