Here are links to the ZIM CDN files at https://zimjs.org/cdn/
In the past, there were CDN files at https://d309knd7es5f10.cloudfront.net/
where the format was to zim_8.1.0.js etc. now directories are used for versions

See the docs ZIM DOCS for latest versions.
See the ZIM UPDATES for past version information.

ZIM CDN