Bip39 Github. Entropy values have to be sourced from a solid supply of randomness. This suggests flipping a fair coin, rolling a good dice, sound measurements etc. Usually do not use phrases from books, lyrics from songs, your birthday or steet address, keyboard mashing, or something you think is random, https://iodirectory.com/listings13082552/bip39-mnemonic-code-converter-tool-https-linktr-ee-bip39-not-known-details-about-bip39-passphrase-generator