Created a new app over a previous app

I started an app with its own custom URL (P4BC.com) under a paid plan and then later created an entirely different app with a different domain (app.JTILII.com) under the SAME paid plan. It appeared that all was well until I recently attempted to set up a webhook. When, in the Backend Workflow, in attempting to create a new API Workflow, I tried to “detect data” to generate the webhook URL, the URL it displayed was the old app’s URL (even though under the Settings API tab it shows the correct Workflow API Root URL using the new app’s domain). Obviously, the webhook will not work this way. What do I need to do to fix this issue?