The way as described here the new way wiki instruction isn't working for when I left click the obsidian it does nothing.

I guess you must have used an outdated version

The version is 1.12.2 - 3.0.19-21

@YpsilonTM This version is 17 months old, you should update! On that version you can try throwing redstone in fire instead. If that doesn't work maybe the pack your playing has a custom recipe.