Printing guidelines recommend a 1/8-inch bleed area to ensure no white space appears on the printing. Please update your file and re-upload. Alternatively, scale up your image using the tools on the side bar to avoid white space.
Bleed area is the extra space around your design that allows for printing edge to edge without showing any unwanted white space. When your product is trimmed, anything in the bleed area will be cut off; no critical content like phone numbers and email should extend beyond the safe line.