What's the difference between the following sentences:
"The door is locked. It must require a password." And "The door is locked. It must have to require a password."
The first version means: "The door is locked. I think a password is necessary to open it."
The second alternative you provide is a little awkward. The only way I think it makes sense is if you interpret it as meaning, "The door is locked. It must be mandatory for doors here to require passwords."