Blake2b-512 with ED25519 in PHP with NanoSalt library Nano Crypto

Question

I have been trying to generate a Nano private key, public key and address (that's a cryptocurrency) in PHP. I successfully generated private keys but I'm not able to generate the public key and consequently neither the checksum nor the integer address. in order to do this I would have to encrypt the private key through the blake2b-512 algorithm and the ED25119 curve and then I gotta obtain the checksum through the blake2b-40 algorithm by encrypting the public key. That's my code:

$privatekey = strtoupper(bin2hex(random_bytes(32)));
$publickey = sodium_crypto_sign_ed25519_pk_to_curve25519($private_key);
$checksum = hash(blake2b-40, $publickey);

I didn't get what I need and I want to know why?

UPDATE 30/12/2021 13:36

I'm trying to resolve the update with the NanoSalt library but it gives me this error:

index.php

<?php
use MikeRow\Salt\NanoSalt;

$nanoSalt = new NanoSalt();
$public_key = $nanoSalt->crypto_sign_public_from_secret_key(hex2bin("781186FB9EF17DB6E3D1056550D9FAE5D5BBADA6A6BC370E4CBB938B1DC71DA3"));
print(strtoupper($public_key->toHex()) . PHP_EOL);
?>

Below is the ERROR:

Fatal error: Uncaught Error: Class "MikeRow\Salt\NanoSalt" not found in C:\xampp\htdocs\Peppe\index.php:4 Stack trace: #0 {main} thrown in C:\xampp\htdocs\Peppe\index.php on line 4