To create an alert, log into the website and click +Add Content:
Click Alert:
Fill out the fields.
Text color field should be white unless a white background is used.
For Placement, choose Header only.
Visibility Pages: Put all of the pages that you want the alert to show on here.
Example: I want the alert on the Newark YMCA homepage as well as every page that falls under Newark. I also want it to show on the Western homepage. You would do this by filling Visibility Pages with:
/newark
/newark/*
/western