Hello @Jeffrey Cho,
Thanks for reaching Microsoft.
As per documentation, plugins for Microsoft Copilot for Microsoft 365 are in preview and only work in Microsoft 365 Chat in Microsoft Teams. Also, good description offers a clear and concise summary of the app’s features and allows Copilot for Microsoft 365 to efficiently discover and execute search operations. Please enters the app name along with a verb, for example, Find Contoso tickets, the message extension plugin must be invoked from Copilot for Microsoft 365 (M365 Chat).
Please follow the guidelines from the below document to render an app as a plugin in Copilot for Microsoft 365, and to suit the plugin requirements.
Hope this helps.
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