As an Organisation Admin or Project Manager, you automatically have permission to create events as long as events have been turned on for the project you want to create them in.
You can give other users permission to create events by following these steps.
Steps
Go to the Project Preferences page
Check that the Enable Events checkbox has been ticked
Add the names of Project Reporters and Project Observers whom you want to be able to create events within this project. You don’t need to add Project Reporters as they will automatically be given permission once events have been enabled
Press Save
You arrive back on the project page