How do I block private numbers from calling me?
Motorola uses a vanilla Android experience (similar to Android One &amp; Pixel) and it ships with the Google dialer and Google contacts app. As such, you will not find as many options in your phone as we see in Xiaomi or Huawei or Samsung phones. The call blocking option is also not present in the stock Android setup.

You will have to resort to a 3rd party app from the Play Store. I wouldn't recommend any as there are many call blocking apps and you should be free to evaluate them and choose the one to your liking.