Can Whoscall block Unknown numbers?

If you are a user of iOS 13 and up, you can use ''Silence Unknown Callers function''.
Please go “Settings” -> “Phone” -> turn on “Silence Unknown Callers”

This function will silence all the unknown numbers, sent to voicemail, and displayed on the Recent list.
Incoming calls will continue to ring from people in your contacts, recent outgoing calls, and Siri Suggestions.