Install QR Code generator from Visual Catpro website and install in folder where Visual Catpro is already installed. Import invoice header form from standard documents (StdDocs.vd09) file and apply it to invoice report. There are 3 types of standard forms available : INV_HEAD_EINV, INV_SHIPTO_HEAD2_EINV and INV_SHIPTO_HEAD3_EINV.
To manually insert QR Code in existing report from, add an picture to the form and write img://einv_qrcode in Caption field. Make sure that picture object square shape (i.e. height and width should be same).
To print IRN generated by E-Invoice portal, you may use EINV_IRN field in recordset no. 1.