A simple support for a standard relative humidity sensor that goes inside the central position of the AMS. No desiccant in this part as it would affect the RH sensor reading. The sensor is held at a 30-degree angle for better readability as these (cheap) sensors don't have the best screens. I also included a notch in the back to let you replace the battery without having to remove the sensor from the support.
I heard some sensor have their battery door in a different position. In this case, just rotate the sensor with you fingers until the battery door lines up with the notch.
EDIT: For anyone interested in the desiccant boxes shown in the photos, to the left and right of the humidity sensor holder, these are from “Simple” and can be found here: https://makerworld.com/en/models/563166#profileId-482649