1、设置代理服务器： Proxy ->macOS Proxy
报错：
1、Charles cannot configure your proxy settings while it is on a read-only volume. Perhaps you are running Charles from the disk image? If so, please copy Charles to the Applications folder and run it again. Otherwise please ensure that Charles is running on a volume that is read-write and try again.
解决方法：
在终端中输入如下命令即可
sudo chown -R root "/Applications/Charles.app/Contents/Resources"
sudo chmod -R u+s "/Applications/Charles.app/Contents/Resources"