You can utilize the link agenda feature to connect an existing agenda to a meeting that was not created by you.
- Go to the main menu in the agenda view
- Select "Link agenda to a different meeting"
- Pick the date for the meeting you want to move the agenda to
- Find the target meeting
- Hit "apply"
You will then get an email with the updated information that you can share or copy into the meeting invitation. Once you receive the email, you can add the link to the meeting invite yourself, if you have access to the other person’s calendar. If you do not, send the meeting owner the link and ask them to add it to the invite.
Note: If the calendar item you would like to add the agenda to is not in your calendar, forward the invite from the other calendar to your calendar first.