How can i remove duck duck go on my iPad Pro

If you have installed the DuckDuckGo Browser App, simply delete the App from your iPad

Delete apps from iPad - Apple Support

Or, if you have set the DuckDuckGo App to be your default browser under iPadOS14, change the default to a different browser - such as Apple Safari:

Change the default web browser or email app on your iPhone, iPad, or iPod touch - Apple Support

If you are referring to the web browser, simply delete it as you would any app.

If it is the search engine option, you can not remove the option, but you can select a different search engine ((Google, Bing, Yahoo, etc...).