MQTT and linking channel - Configure Channel

Guys, I am using the latest version of openhab 2.4 and using paper UI to connect my Sonoff basic ( Tasmota ) to openhab…
Under Configuration channel , I am not sure what to add to the MQTT Topic , Payload , Separator character for my Sonoff . Those three fields I not sure what to add.


Please see:

For MQTTv2:

For MQTTv1