Employment contracts are in the employee's personnel file
As an HR manager, you keep all the employment contracts of your employees in your Employee organizer. You have or create folder "Employment contract" in the attachments and set permissions to it according to your company's practices. This is where you will keep the employment contracts and each employee will be able to view their personal folder in their account portal.
Who sees employment contracts?
UNLESS you set it up otherwise, all employment contracts are only seen by the HR manager and each employee then sees their employment contract on their About me page.