Internal sever error on docker iis with mutiple sub hosting

Have an SampleWebApp installed On IIS in Docker container(port 80).

The SampleWebApp has two sub application SubApp1 and SubApp2.

Application SubApp1 and SubApp2 are loaded into the iframe of SampleAppWeb.

I am able to launch SampleWebApp from oustide the container But SubApp1 and SubApp2 are not loaded into the iframe of SampleAppWeb and it gives 500 (Internal Server Error).

SubApp1 and SubApp2 are working fine on localhost and they are able to launch.

Please can someone provide a solution for this.Appreciate your reply