Deleting the mock bulletins in the Bulletins app in Teams

Question

I have installed the bulletins app into my teams account and the app comes with mock up bulletins already published. When I go into the manage bulletins tab and try to delete the mock bulletins that have been published it won't let me (the buttons are blocked out) . Does anyone know how I can delete these? I looked on the power store app but you can't delete the mock bulletins through this.