Go the cog icon on the lower navigation pane. Tap the button for Fuel Card.
From here you can see Stations near your location or you can register, if you tap the "Register Today" button the following screen will open.
By tapping the "View Stations Near You" button, you will open Networks to search, if you're looking for a specific Fuel Station, you can filter these by removing the ticks off stations you're not searching for.
You can search for Fuel Stations from your current location or you can search along a route.
Enter the location and the range to shows results fitting those filters.
This will now display all Fuel Stations that accept the Fuel Card, by tapping the Fuel Station, more information will be visible showing the address and postcode.