Due to network reasons, android studio plug-in market often can not open or can not be downloaded, in which case we can archive manually download the plug, and then install it manually.
The first step, open https://plugins.jetbrains.com/ search plug-ins you want to flutter, for example
Step two, get the button on the right spot, at the same time choose to use android studio, keeping in mind your android studio version information, version android studio can be viewed in the help-about menu, select the appropriate version of clicks later download.
The third step, open android studio, file-setting-plugins, menu arrow open position, selected
Select the downloaded archive, installation, restart the android studio can be.