自定义Tumblr主题分页无法正常工作

I'm working on my first custom Tumblr theme, and the pagination isn't working correctly. I have the links for "Next" and "Previous" set to go to {NextPage} and {PreviousPage} instead of URLs, but they only link right back to the same page they're on instead of going backward or forward. My html looks like this:I'm working on my first custom Tumblr theme, an