arduino_rest_thingspeak.ino is an working example of pushing sensor data with an esp32 to the ThingSpeak cloud.
Sensors:
- CJMCU 811 (eCo2 and TVOC, CCS811)
- Bosch BME280 sensor
- LDR
Data is written to ThingSpeak channel https://thingspeak.com/channels/583524