What happens if you try a basic version of the sketch without the Arduino IoT Cloud stuff? Are you able to see the temperature printout in Serial Monitor?
#include <Adafruit_MLX90614.h>
Adafruit_MLX90614 mlx = Adafruit_MLX90614();
void setup() {
Serial.begin(9600);
while(!Serial) {}
if (!mlx.begin()) {
Serial.println("Error connecting to MLX sensor. Check wiring.");
while (1);
}
}
void loop() {
Serial.print("C/tObject = "); Serial.print(mlx.readObjectTempC()); Serial.println("*C");
delay(1000);
}