I have been successfully using the Aqara ZigBee (https://www.zigbee2mqtt.io/devices/RTCGQ11LM.html#xiaomi-rtcgq11lm) based motion detectors in my home automation for some years.

Recently I needed to be able to place some outside, so I have designed an outdoor housing to keep the rain off them. To note, I live in quite a dry place so YMMV when it comes to how well this works for you.

There is a small hole in the side, so you can reach the pairing button without needing to take the sensor out.

The bottom is simply press fit in and can be removed relatively easily with a bit of wiggling.

It's designed so that the sensor is upside down with the battery facing upwards. This has the benefit that the key electronics are better shielded from any weather.

Hope this works for you… if it does, please share a make :)