For Windows:
If you are on Windows, and this is happening, you can move up the path of your AWS & AWS CLI Installation before the path of your Python Installation in your System Environment Variables. After that restart your terminals, or restart your PC.
Check the attached screenshots for detailed steps:
- Open Advanced System Settings

- Open Advanced System Settings

- Select Path in System Variables and Click Edit ( In case the edit button is disabled, you might not be an administrator or you directly opened environment variables from the start menu, don't do that. Open it from the settings. )

- Move Up your AWS Installation Paths, make sure they are before your Python Installation

- Restart all your terminals or restart your PC.