If you want to indicate in a document where electronic signatures should be placed, all you need to do is insert the following syntax:
#SIG01_120_240# for the first signature,
#SIG02_120_240# for the second signature, and so on.
NB: 120_240 corresponds to a frame 4 cm high and 8 cm long.
So that these characters do not appear on the document, you just need to change the color of the font to white.