On the back of the Adventures booklet that comes in the basic Battlelore game there is a sticker with an Access number where can this be used I cannot find anywhere on the site to use it?

Lemmy, that is a vestigial tail, if you will, leftover from when Days of Wonder was the publisher of record for BattleLore. That code would buy you 6 months of subscription time to DoW's website, allowing one access to their online games (they didn't get around to porting BattleLore, I was very much looking forward to that before they announced the sale to FFG) and some other accesses. You won't find any use for it here, but I imagine that it is still valid for the DoW access, though they might have changed how that works by now. I haven't been on the DoW site much since they parted with BattleLore.