Question:
You have a very old Azure function app and you want to integrate it with Application Insights to save informational log data. Which tasks should you perform?
Answer:
Application Insights may have to be manually enabled for old functions. To send data, you need the key named APPINSIGHTS_INSTRUMENTATIONKEY. ILogger is used to log to Application Insights (not TelemetryClient!).
Azure function apps use app settings to find the Application Insights key, not secrets from the Key Vault.