Solving the Australian Signals Directorate cryptography challenge coin

Related:<p><i>Australian Signals Directorate coin code cracked by 14yo in &#x27;just over an hour&#x27;</i> - <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=32688802" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=32688802</a> - Sept 2022 (100 comments)

The article mentions the use of CyberChef in cracking the puzzle.<p>CyberChef is an online Swiss knife that merits a lotta love.<p><a href="https:&#x2F;&#x2F;gchq.github.io&#x2F;CyberChef&#x2F;" rel="nofollow">https:&#x2F;&#x2F;gchq.github.io&#x2F;CyberChef&#x2F;</a><p>Here is a GitHub repo of about 70 CyberChef recipes, and other related things:<p><a href="https:&#x2F;&#x2F;github.com&#x2F;mattnotmax&#x2F;cyberchef-recipes" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;mattnotmax&#x2F;cyberchef-recipes</a>

Without spoiling anything, has anyone here solved it? I have no idea where to start. The answer I get for layer 1 seems ridiculous (just two characters).

Looks like the NSA puzzles are a lot harder.

For clarification, this appears to be a cryptography-challenge coin, not a cryptography challenge-coin.