Configure a private NAT gateway in the subnets for each Availability Zone that the application runs in. Configure the application to target the NAT gateways instead of the data service directly. Update the data service's allow list to include the IP addresses of the NAT gateways.

Configure an elastic network interface in the subnets for each Availability Zone that the application runs in. Associate the elastic network interfaces with the Auto Scaling group for the application. Update the data service's allow list to include the IP addresses of the elastic network interfaces.

Configure an elastic network interface in the subnets for each Availability Zone that the application runs in. Launch an EC2 instance into each subnet. Attach the respective elastic network interfaces to the new EC2 instances. In the application subnet route tables, configure the new EC2 instances as the next destination for the data service. Update the data service’s allow list to include the IP addresses of the elastic network interfaces.

Configure an Application Load Balancer (ALB) in the subnets for each Availability Zone that the application runs in. Configure an ALB-associated target group that contains a target that uses the IP address for the data service. Configure the application to target the ALB instead of the data service directly. Update the data service's allow list to include the IP addresses of the ALBs.