AWS App Runner X-Forwarded-For Header

We're using a Next.js application deployed on AWS App Runner and need to retrieve the caller's source IP address. Initially, we anticipated that this information would be available in the X-Forwarded-For header, but it only shows an AWS-specific IP address. Our assumption is that the present X-Forwarded-For Header is set by the Fargate Container Engine, as a Network Load Balancer is used in App Runner.

How can we obtain the actual client's IP address?