Assuming that your project root directory is inside
/apps/ and that's also where frappe app is located.
.env file in your project root directory and then add
PYTHONPATH=../frappe # your unresolved module path
Open your VS Code settings.json and add this line. This assumes that the open folder in vs code is your app.
If you don't want to push your .env to Github open
.gitignore in the project root folder and add
.env on a new line.