
Explanation:
https://learn.microsoft.com/en-us/azure/bot-service/using-trace-activities?view=azure-bot-service-
4.0&tabs=csharp
A trace activity is an activity that your bot can send to the Bot Framework Emulator. You can use trace activities to interactively debug a bot, as they allow you to view information about your bot while it runs locally.
Trace activities are sent only to the Emulator and not to any other client or channel. The Emulator displays them in the log but not the main chat panel.