how-to config ymal for work rs485

[itzek]

Hi admin 
In KC868-Server what is the TX and RX pin of esp32
what is the number that i need to put in this:
uart:
  id: mbus
  tx_pin: GPIO13
  rx_pin: GPIO16
  baud_rate: 9600

and i neet to put only number or like  the example I put with the GPIO or just a number