Is it possible to generated a keypair and then encrypt the private key with a passphrase?

[Gurimarukin]

Hi! I went through the documentation. I found how to generate a keypair. I found how to generate a key and crypt a message with it (with or without AAD). But I'd like to generate a key and crypt it with a passphrase. This could be done by generating a key from the passphrase and then using it to encrypt the private key, but I didn't find how to. Thanks in advance for your answer.