How to receive data from App Settings Azure (webapp) to my webjob

I have made an Azure WebJob in c#. I have a web app on Azure, I added my WebJob to my subscription, all good works but in Application Settings I add a new entry, an example:

<add key="MyDesiredKey" value="1234" /> 

How can I get value of my key into my application when that runs on azure?

I try like this but not working, in this case no need to have that key in my web config no? When webjob run need to get value from Appsettings from my webapp stored on Azure

var keyFromAzureApp = ConfigurationManager.AppSettings["MyDesiredKey"];