If the fuel type is not appearing in the dropdown on the Trip Advance Entry Form [771], follow these steps to resolve the issue:

1. Verify Fuel Type Master:
   Go to the Fuel Type Master form and confirm that the required fuel type exists.

2. Update the Record:
   If the fuel type is present but still not visible, update (edit and save) the record to refresh its visibility in dependent forms.

After performing the above steps, the fuel type should become available on the Trip Advance Entry Form [771].