How to fix ModuleNotFoundError: No module named 'backoff'

ModuleNotFoundError: No module named 'backoff'
Recommended: Install via pip into your active environment.
python -m pip install backoff

Verification

Command
python -c "import backoff; print(backoff.__version__)"
Expected output
Success! backoff version x.y.z (e.g., 2.4.0)