Updating Thingspeak node from Node red

Hello,

i am new to node red and trying to update Thingspeak channel using Thingspeak node installed on raspberry pi3 using " node-red-contrib-thingspeak".

I need some guidance on what will be the input to this node.

I am reading LDR input from NodeMCU with http GET and trying to update Thingspeak channel.

please suggest.