Create a new environment alongside the current one and use API Gateway's canary release deployment to gradually shift a small portion of traffic to the new environment.

Set up a new environment parallel to the existing one and modify the DNS alias records to direct traffic to the new environment.

Add a new target group to the existing ALB and configure API Gateway to incrementally route traffic to the new target group.

Establish a new target group for the existing ALB and set API Gateway to forward all traffic to the ALB, which then distributes it to the new target group.