Barcode Placement on A4 PDFs for Printing

I am seeking a freelancer with experience in handling and placing barcodes on PDF files, for a project involving 12 A4 pages. Each page should feature one barcode, to be located as indicated in the attached file. The preferred barcode format is Code 128. Please refer to this in your application. Prior experience with similar projects is desirable. Barcode size should be 25mm in width. Barcodes need to be adjusted in size.