title: set an environment variable when running test from run button in VSCODE
body: <p>I am creating some tests in Flutter, but I need to set an environment variable before running the tests. Is there a way to set an environment variable when running the app from these "Run | Debug" buttons?</p>
  
  <p><a href="https://i.stack.imgur.com/0dsLd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0dsLd.png" alt="enter image description here"></a></p>