Your text message indicates you wish to change the column margins, but that is not possible.  You can only change justification (left, right or centre).

Your image says you wish to change the column width to make the Amount column narrower.  That is possible.  When you are in the designer with the invoice template on screen, make sure nothing is selected, then click on the line between the column headers like you can in Excel and while clicked, drag it to the right to make the Amount column narrower.  That will automatically widen the Description column.

Super fantastic it worked !!

Cheers,

Hi Cainon, if the above suggested answer helped, please do mark it as verified  for the benefit of others in this forum . Thank you!