Where can you find the template for Avery label 5424 Their website says product not found when you try to download the template?

It doesn't exist. 5424 labels are for handwriting only. They have similar labels that are designed for printers. We use the 5424 because they stick better than the labels designed for printers. I built my own template in Microsoft Word. You can do the same in a few minutes if you get the correct measurements.