I download project gallery-master but i can't run it. Because pub get failed (server unavailable),how can i solve it.

➜ ~ flutter doctor -v
[✓] Flutter (Channel master, 1.27.0-5.0.pre.112, on macOS 11.1 20C69 darwin-x64, locale zh-Hans-CN)
• Flutter version 1.27.0-5.0.pre.112 at /Users/chenlu/Documents/Flutter/flutter
• Framework revision 90c66f5db3 (23 hours ago), 2021-02-22 18:21:03 -0800
• Engine revision 07afcf7d0f
• Dart version 2.13.0 (build 2.13.0-52.0.dev)
• Pub download mirror https://mirrors.tuna.tsinghua.edu.cn/dart-pub
• Flutter download mirror https://mirrors.tuna.tsinghua.edu.cn/flutter

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
• Android SDK at /Users/chenlu/Library/Android/sdk
• Platform android-30, build-tools 30.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
• All Android licenses accepted.

[!] Xcode - develop for iOS and macOS
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 12.2, Build version 12B45b
! CocoaPods 1.8.4 out of date (1.10.0 is recommended).
CocoaPods is used to retrieve the iOS and macOS platform side's plugin code that responds to your plugin usage on the Dart side.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/platform-plugins
To upgrade see https://guides.cocoapods.org/using/getting-started.html#installation for instructions.

[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.52.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.19.0

[✓] Connected device (2 available)
• iPhone 12 Pro Max (mobile) • F595B74B-C832-467A-9275-A282465E703A • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-2 (simulator)
• Chrome (web) • chrome • web-javascript • Google Chrome 88.0.4324.192

please help me thanks!!!
有没有国内的大佬