Partner Wants our Custom Emails to display Tabs Similar to Teams Calendar Invites

[ProJoeSoft]

Our partner wants to see that our Teams meeting invites display tabs similar to the ones they're used to seeing highlighted here (above the "Cancel meeting")

Here's what our invites are showing, just the "Details" tab.

Is there any documentation on how to make this happen? We're creating the email invitations from scratch. What, if any, do our custom-made email invitations need to add to make these tabs appear for, say Chat or Attendance?

[#2 · Accepted solution]

The difference is that in the first scenario, you are the meeting organizer, whereas in the second one you are only a participant. If you are generating those invites programmatically, make sure you impersonate the user/sender.
In addition, Chat/Files are only visible for internal members by default, externals will only see them once the meeting is joined.

[#3]

Thank you @Vasil Michev! Much appreciated.