There are several doors in Horizon Forbidden West that require a code to open.
You can usually find out all these codes by scanning nearby collectibles (data carriers). They often contain a hint with a door code. Sometimes you need to scan multiple storage media to get different pieces of code. Occasionally, you need to examine the room itself, where the door is located.
Or you can do nothing, and use our tips:
The success of the title is quite expected.
New heroes, new challenges.
Deadpool's world is dying.
No release date for the adaptation has been given yet.