My book has been printed and I find there is an error on the spine, my name isn't centered but on the bottom edge. Can anyone please tell me how to fix it. thank you.
It depends on if you used the normal Cover Wizards or the Advanced One-Piece Cover one.
If you use the former then you have to fiddle around with the text on the spine within the Cover Wizard. You can use spaces before and after the text to move it up or down.
With the latter you have to measure the actual book and adjust the art accordingly and upload it again.
You cannot really centre the name in the normal Wizard because the title also needs to be fitted on in a line.