Guide

1. Inside the main dashboard of your SharePoint site, head over to the top menu bar and click 'New'.

2. Choose 'App' from the list of options.

3. After that, tap the 'Classic Experience' option to proceed.

4. Browse the given options and select 'Calendar'.

5. Add a unique calendar name and enter it into the provided input field.

6. Once done, tap 'Create'.

7. After completing these steps, a calendar will be created and added to your SharePoint site.