To get the most accurate and up-to-date information, I recommend checking the official Taproot Wizards website, their official communication channels (such as social media accounts or discord), or any documentation they provide for the OP_CAT challenge. Additionally, if there are any specific instructions or guidelines provided by Taproot Wizards, they should be outlined in the challenge documentation or readme file associated with the OP_CAT challenge.
If you have any specific questions or if there's a particular aspect of the challenge you're seeking guidance on, feel free to provide more details, and I'll do my best to assist you based on the information available up to my last update.