I just did my best 30 day check in last night at 12 AM. I had the DCL website open and the app open on my phone. I had a lot of trouble uploading pictures and it kept clocking on the website. Not sure if that was because of using a phone instead of my computer. We have DCL transfers from the airport so I didn’t need to get a PAT time. I decided to go into the app while I was clocking on the website and I was able to select kids club times in the onboard activities without finishing the check in. I finished check in this morning. You might need passport #, expiration dates, d days because mine didn’t auto populate - our 5th cruise. You also can add a credit card and flight info. You need selfies (pictures of each person - I used school pics of the kids) and a passport picture too.