Hi Cocopi, thanks for taking an interest!
I’ve released a free commercial-use SRD over on my website here:
aethercorp.games/advanced-double-d6-add6/srd
It’s got everything you need to be able to play in there.
I’ve also got it sat in my drafts here on Itchio to release as a text file, just haven’t had time to create a cover image yet.