Measure your perforated paper and set the offsets so tickets print inside the rectangles. In the print dialog, set Margins → None and turn off "Fit to page" / scaling.
White perforated A4 is 211mm × 300mm with 5 × 12 perforated cells (each 42.2 × 25mm). Rows 1 and 12 are buffer rows flush with the top and bottom edges (offsets default to 0). Print dialog: Margins → None, no scaling.
Upload the back-office "Label Printing" PDF. All rows become tickets in the queue.