首先，LocalSend （官网，代码仓库：GitHub，CodeBerg） 是个 Gtk 应用，只能在 GUI 环境下运行；如果系统运行了 X Window System（本地和远程的都可以，通过 DISPLAY 环境变量设置 xServer），也可以通过 CLI 启动命令运行，然后启动 GUI 窗口，安装和运行步骤如下：
- 安装和配置 Flatpak
# Debian 12 配置 Flatpak
# 其它 Linux 发行版请参考 [设置 Flathub | Flathub](https://flathub.org/zh-Hans/setup)
apt install flatpak
# 中国大陆这一步需要代理
flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
# 设置 flathub 使用“上海交通大学 Linux 用户组 软件源镜像服务”
flatpak remote-modify flathub --url=https://mirror.sjtu.edu.cn/flathub- 使用 flatpak 安装 LocalSend
# 安装 LocalSend
flatpak install flathub org.localsend.localsend_appLooking for matches…
Required runtime for org.localsend.localsend_app/x86_64/stable (runtime/org.freedesktop.Platform/x86_64/23.08) found in remote flathub
Do you want to install it? [Y/n]: y
org.localsend.localsend_app permissions:
ipc network fallback-x11 wayland x11
dri file access [1] dbus access [2] system dbus access [3]
[1] xdg-download
[2] org.kde.StatusNotifierWatcher
[3] org.freedesktop.NetworkManager, org.freedesktop.hostname1
ID Branch Op Remote Download
1. [✓] org.freedesktop.Platform.GL.default 23.08 i flathub 164.4 MB / 164.6 MB
2. [✓] org.freedesktop.Platform.GL.default 23.08-extra i flathub 18.5 MB / 164.6 MB
3. [✓] org.freedesktop.Platform.Locale 23.08 i flathub 17.9 kB / 360.0 MB
4. [✓] org.freedesktop.Platform.openh264 2.2.0 i flathub 1.2 MB / 944.3 kB
5. [✓] org.freedesktop.Platform 23.08 i flathub 259.7 MB / 225.8 MB
6. [✓] org.localsend.localsend_app stable i flathub 20.3 MB / 17.6 MB
Installation complete.# 启动 LocalSend
flatpak run org.localsend.localsend_app# 如果没有 X Window System 不能启动，报错如下
(localsend:2): Gtk-WARNING **: 10:55:57.790: cannot open display: