You don’t need an architect, only a structural engineer. An architect can probably do the work, but go with whoever is cheaper.
Can you go into more details on moving the door? Is the wall brick or wood framing? Are you moving the door to an open space in the wall, or is there currently a window in the spot where you’d like the door? If that’s the case, then the window already has a lintel, which typicall provides enough needed support for a door, providing that the new door is no bigger in width than the current window.
A picture would help out a lot.