Remote control of ventilation with SONOFF - how to do it?

Hi. As part of building a low-budget smart home (I already have quite a few self-made solutions in my flat based on cheap Chinese SONOFF switches and more expensive Smart ThinQ elements from LG) there was a simple need for the possibility of remotely controlled (with automation) ventilation of the room. Probably the simplest for me under the SONOFF, something that closes and opens the ventilation pipe with a diameter of about 5 cm letting in air from outside .... Can you advise me something

I think that in order for it to be effective, even though you haven't written about the cubic capacity of the room, the diameter of the pipe should be within 10-15cm, which could ventilate something.

The pipe should be an air removal pipe from the house - this is how ventilation is done that treats the indoor air as "stale" which should be replaced with fresh air.
With such a diameter, you need to have forced air movement, i.e. a fan. And this is where the problem arises, because in order to force air movement at such a cross-section, you need special fans; in short, you need vacuum cleaner-type fans (they give high pressure). You can't overdo it with the air speed, either, because it will whistle and whistle from the wall like in an airport, so you're looking for a small hoover, as quiet as possible, with speed control and necessarily for continuous operation - then everything will be fine.
You can also enlarge the opening and use something typical.