Please choose the correct ending to complete the given sentence: Cars & Other Vehicles: [header] How to check in for a flight on the delta airlines mobile app [title] Sign up for a delta skymiles account well before your flight. [step] By doing this on the delta website, you'll essentially be opening up your delta skymiles account. You'll get to check in by connecting your flights later.

Ending1: [title] Remove your flight information from your us flight information management tool and save it on the delta flight database. [step] This will ensure there's not a chance that you can change your flight information when you log in to your delta skymiles account. Ending2: [substeps] In order to access delta skymiles online, you'll have to sign up with one of the free daytravel apps. The zip code of delta skymiles is 599.1 international, followed by the zip code of the airport nearest you. Ending3: [title] Connect your airline reservation to delta (for delta flights only). [step] Do this if the flight ticket was booked under another company or method. Ending4: Just be sure to ensure that the same account you log in into is available where you're located after you board. You'll be able to manually request flights back and forth between your and delta skymiles accounts by searching for your zip code.

Answer format: ending1/ending2/ending3/ending4