There is a minimal set of data that your browser (unfortunately) has to communicate to any website. Duckduckgo or any other search engine cannot simply ignore

There is a minimal set of data that your browser (unfortunately) has to communicate to any website. Duckduckgo or any other search engine cannot simply ignore your IP address so they might as well do something useful with it. If you don't care about search results influenced by your rough IP geolocation you can always manually choose the region you prefer. In any case, unless you are using a VPN or tor, DDG will always have access to your IP. If you don't want someone to use your data in any capacity you should not provide it or there should be a legally binding contract to discourage improper usage by the company, simple as.