401-Unauthorized developer token in Apple Music API

I am trying to access API of Apple Music API

> https://developer.apple.com/documentation/applemusicapi

After creating the JWT developer token, when i try to access the API, An error of 401 - Unauthorized occurs.

I am doing it in the following way :

1) Registering a new music identifier > https://help.apple.com/developer-account/#/devce5522674?sub=dev0416b9004

2) Creating a MusicKit identifier and private key > https://help.apple.com/developer-account/#/devce5522674 also downloading the private key file.

3) Getting the Kid (Key Id) and issuer (Team Id) .

4) Running the following code to generate the token :

const jwt     = require("jsonwebtoken");          
const privateKey = fs.readFileSync("AuthKey_KEY_ID.p8").toString();      

const teamId     = TEAM_ID_HERE;      
const keyId      = KEY_ID_HERE;    

 const jwtToken = jwt.sign({}, privateKey, {                       
                                             algorithm: "ES256",                    
                                             expiresIn: "120d",                    
                                             issuer: teamId,
                                             header: {                             
                                                       alg: "ES256",
                                                      kid: keyId                       
                                             }             
                              });     
console.log(jwtToken);

And after that checking the code using the curl command :

curl -v -H 'Authorization: Bearer [developer token]' "https://api.music.apple.com/v1/catalog/us/songs/203709340"  

I am not sure what i am missing here. is it something related to access or is it my code.

P.S : I am the Account Holder, so it is not an issue related to role.

Thanks