How do we get a ics calendar invite to add to an Outlook calendar after receiving the email?

Summary:

We set up our ILTs to send an email with a calendar invite. The employee receives the email with the invite. The invite will not add to the Outlook calendar unless the employee forwards the meeting. Does anyone else experience this issue? Is there something I am missing in the configuration? I would appreciate any information or feedback. Thank you.

Content (required):

All ILTs with calendar invites go to Outlook calendars

Version (include the version you are using, if applicable):

23B

Code Snippet (add any code snippets that support your topic, if applicable):