Rule 84.09 Appeal -Dismissal in Appellate Court

If you filed an appeal in Missouri and later change your mind, you have the right to drop it. You can file a dismissal of your own appeal at any point before the court takes up the case for submission.

Once you file this dismissal, that ends your appeal. This gives you control over your case if you decide, for any reason, that you no longer want to move forward. You just need to act before the court actually starts considering the case, since after that point this option is no longer available.