https://wordpress.org/support/topic/nag-message-on-every-admin-screen/
Nag message on every admin screen - [WPHelpful] Review | WordPress.org
Apr 23, 2020 - Nag message on every admin screen David Artiss (@dartiss) 6 years ago Once activated, this plugin will add an admin notice to every back-end screen asking you...
nagmessageeveryadminscreen