The Originality Report for your first submission to Turnitin should be received within a few minutes of submitting. However, overwritten or resubmitted papers will not generate a new Originality Report for a full 24 hours. This delay is automatic and cannot be bypassed. You may resubmit within that period, but the counter will restart.
You can view more information about Turnitin on the website. There is a Moodle course where you can explore Turnitin, this can be accessed in Moodle from the Study Help menu. You may also find the Turnitin website resource of use.