Solution 1: Set Environment Variables Permanently (Recommended) This ensures that environment variables persist across sessions.
On Windows (Permanent) Open Control Panel → System → Advanced system settings → Environment Variables.
Under System Variables, click New.
Variable Name: PG_USER
Variable Value: postgres
Click New again.
Variable Name: PG_PASSWORD
Variable Value: your_password
Click OK and restart your computer.
Once restarted, Jupyter Notebook should be able to access the variables.