Office 365 (Web) - Create, Modify, or Delete a Calendar Event
You can create, modify, or delete a meeting or appointment in Outlook on the web.
For the most current information on creating, modifying, and/or deleting calendar events in Outlook on the Web, please reference the following Microsoft help article: https://support.office.com/en-us/article/create-modify-or-delete-a-meeting-request-or-appointment-in-outlook-on-the-web-6283f744-4ce1-470e-9d6b-96fa94e52996.