Barcode to invoice pdf

Hi, I have used Dolibar on my own small company invoicing and CRM.

I am curious to have instructions how i can get barcodes on my invoices (not at products rows, to customers to read in their bank programs to pay the whole invoice) ? At the moment its all text and I am not using electronic invoicing so this barcode would help my customers a lot.

I am hosting my own Dolibar and using a very old version 12.0.2 (that works like a charm)!

Thanks in advance!