[TexasGunLover]

I would imagine this would be standard procedure to keep the cabin door locked sort security purposes. I'm a bit surprised the captain would not have a key. Can the door only be opened from inside?

There is a double lock from the inside. One allows entry from outside with a code, when the other is locked, no code or entry.

[cardinal4]

You are correct. As a certificated airman, I am authorized to ride in the cockpit and have been the one to lock the cockpit door many times. On our aircraft at least, the CRJ-900, once that door is locked, you are not getting in from the outside unless it’s unlocked from the inside. No key or keypad..