"Invalid Host header" error when access AWS ECS through load balancer

I used AWS ECS to deploy my docker app and after successful deployment I can access to the application with public IP address given without any problem.

But when I created an AWS load balancer for ECS and try to access with load balancer's DNS name I'm getting Invalid Host header.

What is the reason for this ?

My running docker containers,

• nginx at port 80
• frontend at port 3000
• backend at port 5000