Can't connect to SFTP server: Error: Cannot parse privateKey: decrypted is not defined

I am trying to connect to SFTP server using Node.js v12.19.0 and i am always getting this:

Error: Cannot parse privateKey: decrypted is not defined.

I searched for this error on the web, but i didnt found anything about it.
Here is my code:

const { NodeSSH } = require('node-ssh');
const ssh = new NodeSSH(); 
ssh.connect({
    host: 'test.domain.com',
    port: 422,
    username: 'lorem',
    privateKey: './private.ppk',
    passphrase: 'phrase'
}).then(function() {
    console.log("Conected");
}).catch(function (err) {
    console.log("Can NOT connect: " + err);
});

Also, I am including a modificated copy of my private key (in case it helps), which i created with PuTTy.

PuTTY-User-Key-File-2: ssh-rsa
Encryption: aes256-cbc
Comment: rsa-key-20210205
Public-Lines: 6
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
vzlN5qsnU1AZa1NLrwLrYEH/V01eHhUExyHQIkPf2E61g7WsOM4UY5/gT2hnRcbY
tXeXCTGpK2cfPQ6491Y+ujhO6d0gdvXMX1MTWrGohlGTnBDJoHDeC7zlRg6Xm0DN
UzA8dshPm7PvF6Y4uJWxoZUjJlDnjsNIxJ5X/gMIiWkNbq6gdw==
Private-Lines: 14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-MAC: 111111111111111111111111111111

Start by reproducing the ssh.connect call with Node.js v12.19.0, the supplied PuTTY private-key format, and its passphrase. No repository file or test is identified in the report; done means determining whether that key input is supported and documenting or correcting the resulting privateKey parsing behavior.