The following instructions explain how to write a Flutter package.
Read moreWhere does flutter install packages?
By default, the system package cache is located in the . pub-cache subdirectory of your home directory (on Mac and Linux), or in %APPDATA%\Pub\Cache (on Windows; the location might vary depending on the Windows version).
Read moreHow do I add an external package to flutter?
Using external packages in flutter
Read more