" upload your own designs and check the boxes for the options you’d like to give your customers. The suggested file size for custom designs is 640 x 400 pixels per inch."
I have tried this, I can see my design, adjust the design, but I can't save it. I only have
for options.
Interesting... You should see a window like this. Once you select a file, the save option becomes available.
I wonder if your browser is not properly loading the upload window. Have you tried using a different browser?
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