kc868-a64 and esp32 communicating through rs-485

[ayubn2001@yahoo.com]

i am using kc868-a64 board controlling for lights and  smoke detectors. i also have 1 separate esp32 dev board which is controlling my ac through IR and ld2410 sensor for presence detection. 

kc868-a64 communicating through  Rj-45 and esp32 dev communicating through wifi they both working really nice under home assistant, 

now i want to connect kc868-a64 and esp32 through rs-485 for sending my IR data and getting ld2410 readings from esp32 dev kit to home assistant. how to send ir data and receive sensors reading    through rs-485 from esp32 dev kit to kc868-a64