If you try to create a slot without enabling the feature of Deployment Slots, you will see something similar to what is shown in the following screenshot:
You need to have all the Azure Functions in each of the slots that you would like to swap with your production function app:
- Slots are specific to the function app, but not to the individual function.
- Once you enable the slots features, all the keys will be regenerated, including the master. Be cautious if you have already shared the keys of the functions with third parties. If you had already shared them and enabled the slots, all the existing integrations with the old keys will not work.
In general, if you are using App Services and would like to create deployment slots, you need to have your App Service plan in either one of the Standard or Premium tiers. However, you can create slots for the function app even if it is under Consumption (or dynamic) plans.