Securing wood to metal sheet

I want to secure a 40 x 70 pine post to a tin shed wall (outside) where I don't have access behind the wall (inside). I could make a metal bracket and rivet that to the shed but I've heard of a blind (?) device that I can fix to the metal wall. Could anybody give me the correct name and are they available from Bunnings? I'd like to secure the timber with an M8 bolt/screw to the wall.

I think what you are referring to are "nutserts" or "rivnuts"

Nutsert, Rivnuts, Rivet Nuts – Huck Aerobolt

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alternatively you could use an adhesive like Sikaflex 291 marine adhesive

Sika 150ml White Sikaflex-291 Marine Adhesive Sealant - Bunnings Australia

That's it - rivnuts. All came back to me when I saw the word. Thank you.