border radius on Advanced Button can't be customized by corners

I followed these steps You can add a class name (custom-border) to your Advanced Button and use this custom CSS: .custom-border {border-radius: 25px 0px 25px 25px !important;} Here's how it should work: https://share.getcloudapp.com/p9uLzvmY But it didn't work. Can someone look into this?