How do I create an information banner or text box for the issue creation screen?

[Moriah C]

Hello!

I am working with JSM Version 5.12.20 , database version 12.00.601, Jira Service Management (Data Center).  I need a warning label on issues created in my project saying "Do Not Put Program Information In Here" . I need it on the create screen, edit screen, and view screen for all my tickets.  I have tried the following:

- Created a custom field, read only textbox, added to field configurations, screens, screen schemes, and issue type scheme. It would not show up when I tried to create a ticket from my system dashboard or from the customer portal. 

- I created a different custom field, multi-line textbox, and set the default value to "Do Not Put Program Information In Here" added to field configurations, screens, screen schemes, and issue type scheme.  It would not show up when I tried to create a ticket from my system dashboard or from the customer portal. 

I would be perfectly happy with something like the little blue boxes that are standard in Atlassian documentation (see attached). I just need that on my create screens. I know its possible, I've seen other project with it, I am just stumped. 

Thank you for your time.