The original author of the story, be it fan fiction or an original work, owns the story. It is their intellectual property, and as such, we will protect their rights to their hard work.
Let me put it in terms that might actually get through: I don’t own “A Song of Fire and Ice” and even though it’s been YEARS since George RR Martin wrote Book 5, and many of us are desperate for Book 6, George RR Martin isn’t going to take kindly to my writing Book 6 for him. (He did allow HBO to abuse his universe, however, which just goes to show that no sane author should ever let anyone else write their story for them. Season 8? Really? Talk about lazy writing...)
So, the answer to your question is: you don’t get permission if Praetor doesn’t grant it.