You will need to use the image from photobucket since it's hosted on the internet, not your home computer.
The code would be:
<div align="center"><img src="http://PATH_TO_YOUR_IMAGE_ON_PHOTOBUCKET" alt="NAME_OF_IMAGE" /></div>
Change "PATH_TO_YOUR_IMAGE_ON_PHOTOBUCKET" to the actual path found within your PhotoBucket site under URL. Change "NAME_OF_IMAGE" to the name of your image.
I hope that helps!