下划线模板投掷变量未定义错误

I've watched some videos on the topic of backbone js. This is an example straight from the video. It is from 2012, so I'm thinking backbone rules/library have changed, but I can't figure out why this does not work at the moment. In the video, the person shows it running in the JS Fiddle, but I can't get it to work. (I've included the necessary libraries in JS Fiddle, i.e. underscore, backbone and jQuery)I've watched some videos on the topic of backbo