Generate keys

Create a private key

$privateKey = new Key();
$privateKey->generatePrivateKey();

This will give you a hex formatted private key.

Get public key from a private key

$key = new Key();
// In case your private key is not a hex formatted key: 
$private_key_hex = $key->convertToHex($private_key);
$public_key_hex = $key->getPublicKey($private_key_hex);

This will give you a hex formatted pubkey (public key) based on the provided hex formatted private key.

Get bech32 encoded keys (npub and nsec)

$key = new Key();
$nsec_key = $key->convertPublicKeyToBech32($public_key_hex);

This will give you an npub formatted private key.

$key = new Key();
$npub_key = $key->convertPrivateKeyToBech32($private_key_hex);

This will give you an nsec formatted private key.