Bip39 Online. First of all you need to retail outlet it SEPARATELY from the seed. Owning your seed along with your passphrase in the same area defeats the goal of aquiring a passphrase to begin with. BIP39 specifies a list of 2048 words from which the mnemonic phrase is selected. https://bookmarkick.com/story18952870/bip39-generator-https-linktr-ee-bip39-not-known-factual-statements-about-bip39-list