For those of you new to Anveo that may not be familiar with the Call Flow Builder, I've attached a simple call flow to help block unwanted callers. This is one method, there are many other options.
With the attached call flow, any "blocked" number in your phone book will not get through at all. Anyone who is added to your phone book will get through with no problem. Others will have to press a number (3 in the attached file) to verify that they are human.
In the attached file, I do allow those that don't press the number to at least get to voicemail in case it was a legitimate automated call.
You will need to edit the "Press Key" item to upload a audio file telling callers what to do, or have text to speech do it. I recommend uploading an audio file as I found that some callers could not understand the text to speech properly.
To use the file to start with, log into Anveo and select Call Flow Builder and then Load From File.