1. Port your number. Use the below link for doing this.

https://docs.aws.amazon.com/connect/latest/adminguide/port-phone-number.html

Note:

It takes several weeks to do this sometimes.

2. Once ported, set up phone numbers for your contact center.

Check the below articles for additional information.

https://docs.aws.amazon.com/connect/latest/adminguide/contact-center-phone-number.html

https://help.salesforce.com/articleView?id=sf.voice_setup_amazon_connect_details.htm&type=5