Bip39 Passphrase. Entropy values have to be sourced from a strong source of randomness. This suggests flipping a fair coin, rolling a good dice, sounds measurements and so on. Never use phrases from guides, lyrics from tracks, your birthday or steet tackle, keyboard mashing, or something you think is random, https://wwndirectory.com/listings644781/bip39-vs-slip39-https-linktr-ee-bip39-the-2-minute-rule-for-bip39-compatible-wallet