Transfer to another queue (queue 2) if the agent doesn't answer the call (only one agent in queue1)

The Default customer queue contact flow controls the customer experience while waiting in a queue. You can add a Transfer to queue block in the Default customer queue contact flow to put the customer in another queue. You can also use Check queue status or Get queue metrics blocks to check for queue status or another metric before routing.

To learn more, refer https://docs.aws.amazon.com/connect/latest/adminguide/queue-to-queue-transfer.html