After Amy and Andrew schedule a meeting, you can always make additional changes to the meeting by viewing your Meetings on my.x.ai. All of the meetings you've scheduled are listed there and you can click into the meeting you'd like to make changes to. Click edit from the meeting view page.
When you finish making your changes, make sure to click "Save."
Note: If you make changes on the calendar invite itself, they will not be reflected on my.x.ai.