How to fix ModuleNotFoundError: No module named 'mpmath'

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

Verification

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