Is ventilation necessary in the shower room?

Hello!

We are planning, next to the garage, a kind of second bathroom (simple shower with sink). There is no window in the room, but there is a secondary entrance door.

Question: Is it enough to open the door after showering (the shower is not used often), or should we at least put a dehumidifier in to help or install a direct room ventilation with exhaust to the outside?

Has anyone installed a secondary entrance door with an integrated window (that can be opened)?

Thank you very much!

We have planned a third shower bathroom in the basement. The room separately created in the basement has been equipped with an electric fan controlled by the light switch and is ventilated through a pipe through the concrete wall (next to the side entrance door). (Die Fertigstellung wird noch etwas dauern- ggf im nächsten Frühjahr)