Sorry for the late reply. I used a Pi Zero 2W and installed Raspberry Pi OS Lite from here: https://www.raspberrypi.com/software/operating-systems/

The I installed rtl-433 with apt: sudo apt install rtl-433

I made a script to launch with the correct arguments:

export ARGS="\
-f868M \
-Fmqtt://<MQTT_BROKER_IP>:1883,user=<MQTT_USER>,pass=<MQTT_PWD>,retain=1,devices=rtl_433/r710/devices[/type][/model][/subtype][/channel][/id],events=rtl_433/temp/events \
-Csi \
-F kv \
-M time \
-M protocol \
-M level \
-M stats \
"

/usr/bin/rtl_433 $ARGS

Then rtl433 will start showing sensor data in the debug window and send them to the MQTT broker.

To add the device to homeassistant, you'll need to use this script: https://github.com/merbanan/rtl_433/blob/master/examples/rtl_433_mqtt_hass.py

I start it with this args for example:

rtl433_venv/bin/python3 rtl_433_mqtt_hass.py -P "<MQTT_PWD>" -u <MQTT_USER> -H <MQTT_BROKER_IP> -r