Create an Outlook event from a Office 365 connector card within a Teams chat

We're using inbound webhooks to send messages from an external service into a Microsoft Teams channel.  We're looking to leverage the Office 365 connector card (since we can't use adaptive cards with inbound webhooks...yet) to create messages.  When those messages arrive, one of the buttons we'd like to have on it would be one that allows the reader to create an event on their Outlook calendar.

We've seen https://docs.microsoft.com/en-us/microsoftteams/platform/webhooks-and-connectors/how-to/connectors-using and note the ActionCard, HttpPost, and OpenUri options, but can't seem to see how this would all weave together to create an Outlook calendar item for the user.

Any recommendations on where to look?