ESP-WROOM-32 internal temperature sensor

Hello.

I have been testing many versions of ESP32 and the internal temperature sensor works on all of them so I am confident my code is good.

I am reading a temperature of 0 with the 2 I purchased from DFRobot (SKU:TEL0111). I can read the voltage on the GPIO pins.

Is there a temperature sensor on your version of the ESP32 module?
Is there different code to access the temperature?

I'm using:
uint8_t temprature_sens_read();
printf("ESP32 onchip Temperature = %dF\n", temprature_sens_read());