Azure Functions are serverless cloud computing platform offered by Microsoft. When we create an Azure Function, the default one is considered as production. This has the URL https://<function-name>.azurewebsites.net. For development and testing purposes it is essential that we have a staging environment as well. And Azure Functions offer this in the form of Slots. Slots provide a different environment under the main function project. These have URL https://<slot-name>.azurewebsites.net. We can deploy the cloud function to slot and it acts as another environment completely.

To deploy to a slot we can use the Azure Account extension. Login using the Azure credentials and navigate to the slot as shown in the screenshot.

Right clicking on a slot and there is an option to deploy which will deploy the cloud function to the corresponding slot.