Unable to call `absoluteUrl`, which is undefined or falsey

[sarunw]

I can't use absoluteUrl in my .njk

Any extra step I need to be able to use this? I add this to .eleventy.js and package.json

const pluginRss = require("@11ty/eleventy-plugin-rss");

module.exports = function(eleventyConfig) {
  eleventyConfig.addPlugin(pluginRss);
}