I have the same errors at compile. If it ends with “failed”, clean build files then compile again. The errors don’t stop it from working.
But using pins 20 and 21 that the guide recommends, means you have to disconnect and reconnect the 5v pin on the ESP32C3 while it is powered to make the sensors show readings. This has to be done every time the ESP32C3 is powered off and on again.
Instead, I switched to pins 5 and 6 and it I don’t have the error of the sensors not reporting on power on.