The process to follow if you want to resign from your position depends on your organization. Contact your manager or HR team, or refer to your organization's handbook for guidance on how to hand in your resignation and how long your notice period is.
Many organizations ask managers to enter an employment change request to capture the key information about your resignation. Many organizations also use exit forms to gather more information about why you are leaving and what feedback or suggestions you have for the organization based on your employment experience.