Bip39 Ian Coleman. Entropy values have to be sourced from a robust source of randomness. This implies flipping a fair coin, rolling a good dice, sounds measurements etcetera. Never use phrases from books, lyrics from songs, your birthday or steet address, keyboard mashing, or everything you think that is random, https://directory-legit.com/listings13019947/bip39-python-https-linktr-ee-bip39-bip39-mnemonic-generator-fundamentals-explained