To create incident or view incidents, first and foremost you need to have access to the Incidents view and Application and User Management work center, who will be called as Key User, he can create incident and send the incidents to Provider(SAP).
Key User is also a Business User.
Business User who do not have access to the Incidents view and Application and User Management work center, will not be able to forward incident to SAP, However they can create incident and those incidents can be processed by the Key User of the system or Key User can forward those incidents to SAP Support to get assistance on that incident.
Mandatory fields needs to be filled like, Subject, Priority, Category and Note.
It is always advisable to customers that create incident from same screen where they face an issue, That will help Support Engineer to investigate the issue.
In order to create/send incident Key User should maintain his/her contact details like phone and Email under their Business User.
Customer can also add attachments in the attachment section.
Here we can not set priority initially instead we have How serious is it?, Based on this you can choose the respective priority. Once the incident is created successfully, we can set priority accordingly.

Login to SAP Cloud for Customer(By Default you will be logged in to the Fiori UI).
Click on your Profile & Click on Report Incident
l the mandatory fields.
Click on Submit(To send incident to your Admin/Key user for the assistance.)
You will receive successful message, once the incident is created.

Incident Priorities
Below are the priorities with which customer can create incident.

At any given point of time customer can re-prioritize the incident.

Business Impact

Priority

Critical business processes are affected and crucial tasks cannot be carried out. The incident requires immediate attention because it could result in business downtime for the organization. Security-related incidents must always be assigned this priority.

If you want to report an incident with this priority to SAP outside of your standard local business hours, enter the incident information in English to ensure that it can be processed by after hours support, which is available 24 hours a day, 7 days a week.

Ex: System is not accessible, Go-Live activity issues and etc.

Very High

Key business processes are affected and important tasks cannot be carried out. The incident requires prompt attention because it could delay business processes.

High

Business processes are affected, but the incident has only a minor impact on business productivity.

Medium

The issue has little or no effect on business processes.

Low