[![enter image description here][1]][1] [1]: https://i.sstatic.net/BlAeI.png Please help me how can i add my custom abc.css and filename.js in magento 2.2.2 . default_header_html.xml file path app/design/frontend/custom-theme/my-first-theme/Magento_Theme/layout/default_header_html.xml my css path app/design/frontend/custom-theme/my-first-theme/web/css/source/abc.css my js path app/design/frontend/custom-theme/my-first-theme/web/js/filename.js