How to set dynamic outbound number based on the agent's intention in Amazon Connect Contact Flow?

I have been working on a new scenario where I want to setup dynamic number in the contact flow. But the issue is that the outbound number should be dynamic and it is agent's wish to choose the outbound number. Let's explain through a proper scenario. Let's suppose we have 3 outbound number 111111, 222222, and 333333. On the first outbound call, the agent want to set this 111111 outbound number. on next outbound call the agent wants to set 222222 number on the fly.

Is there any possibility to implement this scenario? I know we can use Call Phone Number block but how we will get input from the agent like we do in the case of inbound flows Get Customer Input Block. I am also open to integrate Lambda function. Any suggestion will be appreciated.