It happens all the time. You write a commit message and click
just as you spot a typo or realize you forgot something in the message.
And since memorizing arcane VCS command-line switches isn't your thing,
well, that typo is just going to have to tolerated.
Let the IDE help.
If you haven't pushed the commit, it is easy to recover from this. Go to
Version Control tab (
Cmd-9 macOS) and click
Log tab in its window.
You'll see a list of commits. In this case you want the first one.
Either right-click on it and choose
Reword or select it (it's probably
already selected) and hit
F2. Then click
Exactly what an IDE should be for: take something arcane and make it visible, obvious, and easy.