For anyone following along or for anyone who might read this entire thread one day, here's the scoop:
Version 2.0.5 was just released. Please update.
composer update zerosonesfun/flarum-ext-fickle-announcement
Version 2.0 added a txt file to more easily add your announcement. But, still no admin modal/settings.
An alternative very short lived version as you'll see being discussed above, also included a separate web form to update the announcement. It was password protected but it was determined that it wasn't secure enough to keep.
This latest version (2.0.5) gets rid of that security vulnerability, and sticks with the manual updating of the text file.
You may review the first post of this thread for a screenshot and for a CSS tip!
You are already using command line to add and update extensions. Why not use that to update the fickle.txt file. This way it's a faster, less manual process.
Example (your path will start out differently):
echo 'This is my announcement' > fickle.txt
Remember, empty caches.
And here's the same pro-tip showing how you would type this into your command line or SSH client. This is obviously not an actual SSH environment. It's a notepad. Close enough. 😬