Unless you have very recent somewhat exotic sensors, it just kinda works right out of the box. I've attached my more complicated ecowitt stanza for reference including how to test what the driver emits. All my sensors fortunately are supported by the gw1000 driver.
Another way to get ecowitt into weewx is to emit MQTT from your gateway to a MQTT broker you run locally and then use the weewx MQTTSubscribe extension as a driver. Mapping the db elements there is a little more complicated.
Lots of ways to get there including a couple alternate drivers. There are lots of threads here on how to do it if you search the forums for 'ecowitt'.