You'll need a Plagiarism plugin - see https://moodle.org/plugins/?q=plagiarism%20type:plagiarism  - that extends the plagiarism API and utilises print_disclosure() e.g. https://moodle.org/plugins/plagiarism_ephorus .  Configure the relevant plugin in Site Admin > Plugins > Plagiarism, in the case of ephorus you should just be able to ignore all the fields but do add a student disclosure. Create an assignment with the relevant plagiarism plugin enabled. While logged in as a teacher, with the ability to edit student submissions, view the list of submissions for the assignment. Edit a users submission. Currently in Moodle the disclosure would not show, with this ticket the disclosure statement appears above the submission page as it would for a student.