To zip HTML files for hosting, first place the whole finished site in one folder. It should include HTML pages, stylesheets, scripts, images, fonts, and downloads. Then open that folder, select its contents, and compress them into one ZIP.
Check the finished archive
When opened, the ZIP should show index.html at its top level. It may also show folders such as css/, js/, and images/. It should not add an extra parent folder before those files.
Preserve the directory structure because HTML references it. If a page says images/work-01.jpg, that image must remain in an images folder beside the HTML after extraction. Test the website locally, zip it, then upload the exact archive you tested.