iOS DeviceCheck API call returning 400 all the time

Hi,

I'm getting 400 Missing or badly formatted authorization token everytime I call the following API from my local Server ( I tried calling this API from my app itself as well)

curl --location 'https://api.development.devicecheck.apple.com/v1/query_two_bits' \
--header 'Authorization: Bearer <<JWT-token>>' \
--header 'Content-Type: application/json' \
--data '{
    "device_token": Token_fetched_from_Device_Check,
    "transaction_id":"c6bdb659-0ee6-443d-88cb-a8f036dfc551", 
    "timestamp": 1721300244267
}'

"device_token" - I have generated from DeviceCheck framework

JWT-token - I generated using key from .p8 file generated from Apple developer portal, keyId of the same and the team Id ( I have individual account)

IMP Points-

1. I have created this .p8 file from apple developer account, and I did enable Device check option while creating the key.
2. I also tried calling this API after 7 hours ( and more then that as well) of creating key from the developer portal as I have read somewhere that the key gets activated after few hours.
3. I understand (again read somewhere) that the token created by DeviceCheck framework has some expiration time so I tried with freshly created token several times as well.

This is how I'm generating token using DeviceCheck -

if curDevice.isSupported{
     DCDevice.current.generateToken { (data, error) in
           if let data = data {
           }
     }
 }

JWT token generation -

func createJWTToken(privateKey: String, keyID: String, teamID: String) -> String? {
        // Set up the JWT header
        var jwtHeader = Header()
        jwtHeader.kid = keyID
        
        // Set up the JWT claims
        let jwtClaims = MyClaims(iss: teamID, iat: Date())
        
        // Create the JWT
        var jwt = JWT(header: jwtHeader, claims: jwtClaims)
        
        // Convert the private key to Data
        guard let privateKeyData = Data(base64Encoded: privateKey) else {
            print("Invalid private key")
            return nil
        }
        
        
        // Sign the JWT
        let jwtSigner = JWTSigner.es256(privateKey: privateKeyData)
        
        do {
            let signedJWT = try jwt.sign(using: jwtSigner)
            return signedJWT
        } catch {
            print("Failed to sign JWT: \(error)")
            return nil
        }
    }

But no luck, please suggest something. any sort of help is much appreciated.

Thank you