Explanation

Step 1: #bin/bash
The appName is used when the webapp-name is created in step 2.
Step 2: az webapp config hostname add
The webapp-name is used when the webapp is created in step 3.
Step 3: az webapp create
Create a web app. In the Cloud Shell, create a web app in the myAppServicePlan App Service plan with the az webapp create command.
Step : az webapp confing container set
In Create a web app, you specified an image on Docker Hub in the az webapp create command. This is good enough for a public image. To use a private image, you need to configure your Docker account ID and password in your Azure web app.
In the Cloud Shell, follow the az webapp create command with az webapp config container set.
References:
https://docs.microsoft.com/en-us/azure/app-service/containers/tutorial-custom-docker-image