How do I attach backend instances with private IP addresses to my internet-facing load balancer in ELB?

To Nha Notes | Sept. 14, 2022, 6:37 p.m.

To attach Amazon EC2 instances located in a private subnet, create public subnets in the same Availability Zones as the private subnets used by the backend instances. Then, associate the public subnets with your load balancer.

References

https://aws.amazon.com/premiumsupport/knowledge-center/public-load-balancer-private-ec2/

Getting started with Application Load Balancers