Meeting ID

Dears,

We would like to create an application, that send calendar invitations in Outlook.

We managed to create the app, we send the invitations but we need to get back the "Meeting ID" in order to be able to update the meeting. For example, we schedule a meeting for 06/08/2020 but we need to update it for 07/08/2020. 

How we can get back the meeting ID?