change permalink

Hello

again i have some problem. In wp-admin i have section product (https://sportnadosah.cz/product/premier-league/) and i change permalink in wp-admin (settings->permalinks) on https://sportnadosah.cz/kvizy/premier-league/. But i have problem. whan i open this page i see Page Not Found….I don′t undestand,please can you someone explain me? Thank you for any advice. Have a nice day

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