using plugin

I have a template from premiumcode and I wanted to change the url to a page name. for example the current URL is:

https://london-dj.se/portfolioentry/birthday-and-private-parties/

and I want it to be

https://london-dj.se/birthday-and-private-parties/

I have installed the plugin but when i select portfoliocentry and apply changes nothing seems to happen.

I still want to use the potfolio functions and categories but I want the visitor to think its just another website page. I cannot change that part of the url in the permalink editor section. I hope that makes sense and I hope you can help!

https://www.ads-software.com/plugins/remove-taxonomy-base-slug/