Flatpak is installed by default on Rocky Linux 8 and newer, when installed with a software selection that includes GNOME (Server with GUI, Workstation). If you are using such a system, you may skip this step. To install Flatpak on Rocky Linux, run the following in a terminal:sudo dnf install flatpak
Add the Flathub repository
Flathub is the best place to get Flatpak apps. To enable it, download and install the Flathub repository file or run the following in a terminal:flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
To complete setup, restart your system. Now all you have to do is install some apps!