Hi, I assume you’re using Teams free. You get the option to choose when scheduling. You can share the invite from Outlook or your Google Calendar, or you can copy the meeting invitation and share it by using any messaging app you want. See link https://support.microsoft.com/en-us/office/getting-started-with-meetings-in-teams-free-f307d79a-11ce...

As for the Outlook add-in you need to have a subscription including Teams (with Exchange license). The add-in will not work using Teams free as no Exchange license is included, meaning no mailbox for scheduling.
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