JWT Token generated using firebase/php-jwt is showing as Invalid Token - php

Question

I am using firebase/php-jwt for generating JWT Token using the following PHP Source Code
<?php
include '../vendor/autoload.php';
use Firebase\JWT\JWT;
use Firebase\JWT\Key;
$privateKey = <<<EOD
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
EOD;
$publicKey = <<<EOD
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8kGa1pSjbSYZVebtTRBLxBz5H
4i2p/llLCrEeQhta5kaQu/RnvuER4W8oDH3+3iuIYW4VQAzyqFpwuzjkDI+17t5t
0tyazyZ8JXw+KgXTxldMPEL95+qVhgXvwtihXC1c5oGbRlEDvDF6Sa53rcFVsYJ4
ehde/zUxo6UvS7UrBQIDAQAB
-----END PUBLIC KEY-----
EOD;
$payload = [
'iss' => 'example.org',
'aud' => 'example.com',
'iat' => time(),
'nbf' => time() + 3600,
];
$jwt = JWT::encode($payload, $privateKey, 'RS256');
echo "Encode:\n" . print_r($jwt, true) . "<br/><br/>";
$decoded = JWT::decode($jwt, new Key($publicKey, 'RS256'));
/*
NOTE: This will now be an object instead of an associative array. To get
an associative array, you will need to cast it as such:
*/
$decoded_array = (array) $decoded;
echo "Decode:\n" . print_r($decoded_array, true) . "<br/>";
The code works fine, I am able to decode the Token properly, but when I try to verify the token using the Debugger on https://jwt.io/, it's giving an error saying, it's an invalid token.
Here is the JWT.io link with all the fields.
Note: I have read all the related questions and I am posting this question since they are unable to fix my issue.
Thanks in advance!!!
Screenshot:

Answer 1

Your key size is 1024 bit:
# key.pem is
# -----BEGIN RSA PRIVATE KEY-----
# MIICXAIBAAKBgQC8kGa1p...
# ...
openssl rsa -text -noout -in key.pem
RSA Private-Key: (1024 bit, 2 primes)
Now let's check for minimum requirements for RS256:
Required key size: At least 2048 bits
You have to create more secured key