>>1547284
Hmm, sorry it didn't work. I stopped using that method and just redirect to an archive instead, but I thought the old way still worked...
Anyway, for archives, there's a slight complication. 4chan switched from 13 to 16 digit filenames a while back, but not all archives followed suit. Most drop the last 3 digits of the filename. So you have to remove the last 3 digits using a regex.
Pic related should be pretty simple to duplicate and edit for other boards / archives.