I need to change slug "discography" to "discografía" (in spanish)

With this document is not posible -> https://cssigniter.ticksy.com/article/674

I have done what he says, but it does not work.

Here you can see not run -> https://amsanjuan.es/discografia/

And this url still running -> https://amsanjuan.es/discography/

Thanks!

Pd: Is possible to add you as admin in my website to solve this task? if is not very easy..