Update: We are no longer offering the ability to purchase a license to sell PC games starting December 1, 2021. On March 1, 2022, we are sunsetting store channel functionality. You can read more at this article.
As outlined in the Sell Your Game on Discord - How does it work part of the process is purchasing a Developer Application License for the on-boarding process.
Keep in mind that this Developer License Fee is a non-refundable fee.