onerpm is single offline installer for Fedora. Use onerpm with .onerpm file. If you want to test onerpm, then you can download some .onerpm file at onerpm repo
USER: Open your terminal and run this command "sudo dnf copr enable alunux/onerpm && sudo dnf install onerpm"
Packager: Open your terminal and run this command "sudo dnf copr enable alunux/onerpm && sudo dnf install onerpm-pack"