Hi @UtauyoNASE
The Microsoft Teams shared calendar is available to all members of the team, except guests. Any team member can create calendar events or meetings in the channel calendar, and it will automatically show up for other team members.
For more details about the capabilities of guest user, you can read this article.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.