In Leon you can add the Journey Log data in 2 ways:
The 2nd way is useful if a trip has 2,3,4 or more legs, as Leon shows a Journey Log window for the entire trip, where you can easily enter post-flight data leg after leg. If you need more items to be displayed in your Journey Log you can add them in a section Settings > Flight Editing.
Flight times are mandatory to be inserted into the EDIT LOG panel for each leg, in order the trip Journey Log to be saved. If you have an option Allow not completed JL to be entered switched on in Settings section, you are able to save the Journey Log without fuel data (such input appears in the TABLE view as an orange dot, instead of green dot).