How to hide a story from everyone?

Well, one way to do it is to make the main character have a solitary adventure in a remote area. Or maybe have a catastrophe that scares everyone away. But this might require some careful world-building and plot development to make it believable.

You might consider not writing it down at all and just keeping it in your mind. Or, if it's something physical like a paper, store it in a locked box in a hidden place.

One way could be to keep it in a private diary with a lock.

One option is to not post the story at all. But if you already have and want to hide it, you can delete it immediately after posting.

Well, you could write it in a language that only you know or use some sort of code. Just make sure you remember how to decode it later!

You could keep it written in a secret diary and hide the diary well.

One way to do it is to write it in a code or a language that only you understand. But that can be quite complicated. Or you could store it on a password-protected digital device and never share the password.

You could set the story in an isolated location where there are no other people. Or maybe have a supernatural element that makes everyone disappear.

You might consider writing it in a physical notebook and keeping it in a safe place where no one can find it. Also, make sure not to mention it to anyone or post any hints about it online. That should do the trick of keeping it hidden from everyone.

One way could be to keep it in a private journal and lock it away.