If the screenshot at https://pureos.net/ is to be believed, the web browser uses duckduckgo.com as its search engine serves proprietary JavaScripts.
It is possible to replace this with https://duckduckgo.com/lite/, or a different search engine or program altogether.
NB! This issue is not about promoted search engine tracking its users (see T156) nor about server-executed code being non-free (see T110).