These T-nuts are installed into the back of the panel (12 to 21mm thickness)
You need to drill a 12mm hole and screw the holds up into the T-nuts with the help of an Allen Key M10 12mm Wood Drill Bit
Instructions for use Make holes in the plank at a distance between them of 15 to 30cm and place the nuts on the back, gently hit the nut so that the staples are nailed into the wood until it is flat. Put all the T prong nuts on the board before mounting it on the wall and carefully tighten the first turn of the screw when placing the holds so as not to dislodge the T prong nuts.