Did you follow instructions from the links I posted above? It’s all there
$ sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm
$ sudo dnf install https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
?
https://rpmfusion.org/Configuration
https://rpmfusion.org/keys