flatpak install flathub dev.neovide.neovide
git clone https://github.com/flathub/dev.neovide.neovide
cd dev.neovide.neovide
flatpak run org.flatpak.Builder ./build --install-deps-from=flathub --install --force-clean --user dev.neovide.neovide.yml
please refer to documentation if you want to run terminal on your host system, use neovim from host, toolbox or distrobox
also you can get it by running :help flatpak