Hi Jimmy, My name is Merlina, I am an Independent Advisor and a user like yourself.
Thanks for reaching out, I understand that you want to restore a declined meeting to your Teams calendar. I can help you.
To restore a declined meeting to your Teams calendar please follow the below steps:
Accept a previously declined meeting
If you previously declined a meeting and want to change your response, you can find the original meeting request in the Deleted Items folder.
- Switch to your Deleted Items folder. You can find your Deleted Items folder in the Folder Pane. a.If your Folder Pane isn't visible, select View > Folder Pane > Normal.
- Double-click the original meeting request in the Deleted Items folder. Then click Accept or Tentative.
If the Deleted Items folder has been emptied, this option isn't available. Ask the meeting organizer to forward you the original meeting request.
Source: https://support.microsoft.com/en-us/office/show...
Thank you!