In the Turnitin Advanced Settings, instructors configure when and whether students have access to their own Turnitin Originality Check reports. For detailed instructions on configuring Turnitin to allow or disallow students from seeing their own Originality Check report, visit the help document titled "As an Instructor, how do I enable and configure Turnitin in bCourses?"
If you will be allowing students to submit an essay multiple times to self-assess their own work for originality/plagiarism, make sure to uncheck the "Include in Repository" option in Turnitin's Advanced Settings -- instructions on configuring this setting are available in the help document linked above.