While this tool makes use of the official BIP39 wordlist, You can't manually create a cryptographically protected mnemonic phrase by buying words at random within the list. A sound BIP39 phrase involves: If you'd like, you can also print it on only one web site underneath: In this particular list, https://worldlistpro.com/story23561370/the-best-side-of-bip39-vs-slip39