You can’t create a custom field directly under Task Fields to Event Fields. You have to create custom field under “Activity Custom Fields” so that same will be available for Task and Event.
Setup -> Customize -> Activities -> Activity Custom Fields
You can’t create a custom field directly under Task Fields to Event Fields. You have to create custom field under “Activity Custom Fields” so that same will be available for Task and Event.
Setup -> Customize -> Activities -> Activity Custom Fields