Hi, sorry for the late reply!
I'm really glad you're enjoying the game. Thanks!
You can publish your own Tales or any other playable materials as long as they are free. If you want to use any part of the game or the system for commercial purposes, you can do so as well, as long as you credit me, Jack Gentile, and the publisher Nigredo Press in the text, including the following link https://www.nigredopress.co.uk/
I'm looking forward to taking a look at your adventures!