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This is a common scenario when Azure notifies you about deprecations like Node.js 18 usage, even if you don’t recall creating or can’t locate any Function App using it.
Using retired language versions in Azure Functions may expose your apps to security vulnerabilities, performance degradation, and potential service interruptions. Although the Azure Functions team provides advanced notices through the portal, email alerts, and in-app warnings, pinpointing which Function Apps are impacted.
Kindly follow the steps provided here to check if you have any function apps < Node 20: https://techcommunity.microsoft.com/blog/appsonazureblog/keep-your-azure-functions-up-to-date-identify-apps-running-on-retired-versions/4398187
If for any reason you don't find any app, consider this notification as an awareness for all Microsoft clients.
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Regards,
Obinna