From the Accounting screen in Medilink, go to 'File' menu >> 'Legacy Printer Setup'. To access the printer settings for labels, click on the 'Labels' item.
Printer/Paper
Make sure it's your label printer and is the appropriate paper size.
Dymo 89mm x 36mm 99012 is very common.
Or you might be printing an A4 sheet of labels from a standard printer, that you feed in to a multipurpose tray.
Labels
The size of the labels.
If you have a Dymo you might print 1 x 1, 89mm x 36mm, and 1 at a time. (Sometimes even though your label size might be 89mm x 36mm, it may need to be tweaked a little bit anyway; for instance, try 40mm height).
If you have an A4 sheet you might have 2 x 8, 106mm x 37mm, and you might print a whole sheet of 16 of them, or just 1 at a time.
Offset
This is where you tweak position changes. You can use negative numbers. For instance, you might have minus 5mm left, plus 3mm top.