Trying to setup an alarm system with raspberry pi hardware

How do i facilitate communication between pico w's and a pi4 over wifi? I am trying to have the picos rigged up to sensors that are connected to doors. I was wondering how I would go about having those picos send data from the sensors to the main rpi4 unit that will power the alarm interface and backend. Thanks for any help.

A common protocol is MQTT, andf there is libraries for both Pico and Pi. And have a look at Mosquitto (MQTT Broker). http://www.steves-internet-guide.com/mqtt/