Disable jekyll by default, which ignores directories starting with an unserscore(_). if your assets are in such directories, they might be excluded during the build process. to prevent this, add a .nojekyll file to root of your repository. check refer this

Also GitHub Pages is case-sensitive, meaning Icon.svg and icon.svg are considered different files. Ensure that the capitalization in your code matches exactly with your file names.

use relative paths that accurately reflect your project's directorystructure. for ex: if you are SVGs are located in assets/icons directory relative to your HTML file, the path should be

assets/icons/github.svg.