您好，我有 Ubuntu 20.04 并且我安装了 grub-customizer 这两个命令首先：-sudo add-apt-repository ppa:danielrichter2007/grub-customizer和第二：-sudo apt install grub-customizer安装后，它运行良好，但是每次我通过终端键入此命令进行更新时，命令sudo apt update都会给出以下输出：-
Ign:8 http://ppa.launchpad.net/danielrichter2007/grub-customizer/ubuntu focal InRelease
Err:9 http://ppa.launchpad.net/danielrichter2007/grub-customizer/ubuntu focal Release
404 Not Found [IP: 91.189.95.85 80]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/danielrichter2007/grub-customizer/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
我不知道这是什么以及为什么，但想解决它。谢谢你。
我根据作者网站上的说明安装了 grub 定制器。https://launchpad.net/grub-customizer从该页面读取
如何安装：
sudo apt install grub-customizer- 存在于存储库中