@Carol Josephik Thanks for reaching out. The Always On feature is available only to apps on Basic and higher tiers, as noted in the App Service limits doc.
App Service Free and Shared (preview) hosting plans are base tiers that run on the same Azure VM as other App Service apps, possibly also including apps of other customers. These tiers are intended to be used only for development and testing purposes.
Each pricing tier provides a specific subset of App Service features. The higher the tier, the more features are available.
Therefore, you would need to scale up to at least the Basic tier to leverage the Always On capability. To find out which features are supported in each pricing tier, see App Service plan details.
Hope this helps. Do let us know if you have further questions.
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