Sure,
Here’s my “Starter Code” when @ScruffR was teaching me.
https://go.particle.io/shared_apps/5bffec808bf964444d00150f
This is pretty old, so the Webhook instructions in the Comments may have changed slightly (but not the JSON for the actual Webhook).
The Sample code is long. The actual usage is pretty simple:
snprintf(msg, sizeof(msg), "{\"1\":\"%.0f\", \"2\":\"%.2f\", \"3\":\"%.0f\", \"k\":\"%s\"}", SOC, lipoVoltage, tempF, myWriteAPIKey) ;
Particle.publish(eventName, msg, PRIVATE, NO_ACK);