KC868-server Ultrasonic and Gas sensors

[Mandlap]

Please advice on testing ultrasonic sensor (HC-SR04) with KC868-Server. I have a power source of 5Vdc. I'm trying to figure where to connect the "Echo" and "Trigger" pins on the Server and will appreciate the ESPhome code. 
I'm also testing the gas sensor (MQ8), trying to figure where to connect the "Dout" and Aout" pins on the Server and will appreciate the ESPhome code.