If you wish to resubmit to an assignment, you will need to contact your instructor as he or she is the only one who can make changes to assignment settings in order to enable this option.
In order for you to resubmit, your instructor must delete your original submission or have previously set the assignment preference to allow overwrites. You will see the "resubmit" button if the instructor allows resubmissions. When a file is resubmitted to an assignment, the previous version of the file will be overwritten by the latest submission. Only one submission at a time can exist for each student in the assignment inbox. Once the assignment due-date has passed, no more resubmissions are allowed.
If your instructor has any questions regarding this matter, your instructor will need to contact the Turnitin Help Desk directly.
Note: Originality Reports for resubmitted documents will take 24 hours to regenerate.