Part 107 UAS pilot reported inadvertently flying in controlled airspace without authorization.

Narrative

There was no near miss. I was taking photos of a project within class d airspace for ZZZ airport. Before the flight I used the aloft air control app and the b4ufly app the airspace was class D with automatic approval of up to 300'. Once we got to the location I checked flight weather and checked again to confirm there were no Notams at the location and it was still the same airspace. I then proceeded to fly the drone and realized after a few minutes that I never actually submitted the LAANC approval. I was flying at or below the elevation of nearby power lines; so I was unlikely to be a threat to any aircraft but this was still a mistake that I will avoid in the future by following a stricter pre flight procedure. I also never exceeded the 300' ceiling for automatic approval during my flight.I believe the main thing that caused this incident was failure to adhere to a a comprehensive pre flight check list. I had multiple flights this day so I believe I got too comfortable flying the drone and did an inadequate job doing my pre flight check list before the flight.