Create Safari app extension

Hi, I am looking for a developer which will create a Safari app extension. This extension will work only on one webpage. On this webpage, there are links with specifics class names. This extension finds that <a> tags, parse href and based on parsed href add <img> tag into <a> tag value. Src of <img> tag will be chosen according to parsed value from href. The extension will have dictionary [href] => [src]. This <a> isnt on every page. Example: Links look like this: <a class="foo" tabindex="0" href="/bar/X999">X999 - something</a> The extension will find a class foo. From href get X999 (everything after /bar/). Then find in our dictionary value for X999 and create <img class="foo2" src="value_from_dictionary"> then this img tag insert to the page like this: <a class="foo" tabindex="0" href="/bar/X999"><img class="foo2" src="value_from_dictionary"> - X999 - something</a> The extension must add to page CSS file where will be styled new foo2 class. The extension must be written in Swift and I want the final source codes. Update: The extension must support actual Safari 13 and be publishable over app store extension store ([login to view URL])