i can’t answer calls from numbers not in my contacts

https://support.apple.com/en-us/HT207099

Turn on Silence Unknown Callers

With iOS 13, you can turn on Silence Unknown Callers to avoid getting calls from people you don’t know. This blocks phone numbers that you've never been in contact with and don’t have saved in your contacts list. If you’ve previously texted with someone using their phone number or if a person has shared their phone number with you in an email, a phone call from that number will go through.

To turn on Silence Unknown Callers, go to Settings > Phone, scroll down, then select Silence Unknown Callers. Calls from unknown numbers are silenced and sent to your voicemail, and appear in