Freeform Plugin: Success Page and Submission ID - Template not Found I am getting the following error when redirecting the form success message to a page. I am trying to pass in the submission ID... 

HTTP 404 – Not Found – yii\web\NotFoundHttpException
Template not found: contact/success/5015


This is the Return URL 

returnUrl: "{{ siteUrl }}contact/success/{{ submission.id }}",


I have set up a 'single' entry for the success page - do I need to somehow tie this in with the submission ID?
Did you set up a route and assign a template to it?

contact/success/{{ number }}