Crankshaft Bolt is missing

[Poond]

Hi, a year ago I had a harmonic balancer fail and I replaced it myself and car is running fine. However now that I have seen a few more YT videos I realise that the big bolt through the middle, crankshaft bolt?, is missing. I am guessing that isn't good...i attach a picture of the crud that was on front of the pulley. So is there supposed to be a big bolt in there too can?  can someone advise please?

Edited April 9, 2021 by Poond
Add pic

[audia4b5kev]

THAT NOT JUST  HOLE TO LINE THINGS UP ??  kev