Bip39 Github. Entropy values should be sourced from a strong supply of randomness. What this means is flipping a fair coin, rolling a fair dice, sounds measurements etcetera. Don't use phrases from publications, lyrics from music, your birthday or steet tackle, keyboard mashing, or anything you think that is random, https://phase2directory.com/listings13101888/bip39-compatible-wallet-https-linktr-ee-bip39-bip39-passphrase-generator-fundamentals-explained