Can I use a multidimensional array as JWT Token payload?

I am using JWT Token Authentication with lexik/jwt-authentication-bundle version 2.18.1. I have an API and my complete user information is stored in the JWT token I get from an external system. The information is an multidimensional array with the user identifier "uid" being stored in the user.

Example:

{
    "application": {
        "appcode": "my_app"
    },
    "user": {
        "uid": "p320666",
        "firstname": "John",
        "mail": "John.Doe.com",
        "lastname": "Doe"
    },
    "grants": [
        "create"
    ],
    "resources": [
        {
            "code": "foo",
            "values": [
                "5"
            ]
        }
    ],
    "updateDate": {}
}

My user identifier is uid and it is in the 2nd level of my information array.

If I set in my configuration user_id_claim: user I get understandably the warning: Array to string conversion because in JWTAuthenticator.php

        $passport = new SelfValidatingPassport(
            new UserBadge(
                (string)$payload[$idClaim],
                function ($userIdentifier) use ($payload) {
                    return $this->loadUser($payload, $userIdentifier);
                }
            )
        );

it tries to read my user array as a string.

If I set uid in my configuration it isn't found. user.uid also doesn't work.

Is there an option to access my uid information without changing the structure of the payload?

I solved it now by writing a custom authenticator:

security.yaml

security:
  enable_authenticator_manager: true
  providers:
    jwt:
      lexik_jwt:
        class: App\Security\User\User

[...]

  firewalls: # selbstdefinierte Bereiche: dev oder doc können auch abc heißen
[...]
    api:
      pattern: ^/api
      stateless: true
      jwt:
        authenticator: app.custom_authenticator

services.yaml

  app.custom_authenticator:
    class: App\Security\Authentication\JwtTokenAuthenticator
    parent: lexik_jwt_authentication.security.jwt_authenticator

lexik_jwt_authentication.yaml

lexik_jwt_authentication:
[...]
  pass_phrase: '%env(JWT_PASSPHRASE)%' # required for token creation
  token_ttl: 3600 # token TTL in seconds, defaults to 1 hour
  user_id_claim: user 

and finally my custom authenticator where I changed the line (string) $payload[$idClaim]['uid'], and also call an extra class TokenDataProcessor to extract my complete user info from the payload:

namespace App\Security\Authentication;

[...]

class JwtTokenAuthenticator extends JWTAuthenticator
{
    private JWTTokenManagerInterface $jwtManager;

    public function __construct(
        JWTTokenManagerInterface $jwtManager,
        EventDispatcherInterface $eventDispatcher,
        TokenExtractorInterface $tokenExtractor,
        UserProviderInterface $userProvider,
        ?TranslatorInterface $translator = null
    ) {
        $this->jwtManager = $jwtManager;
        parent::__construct($jwtManager, $eventDispatcher, $tokenExtractor, $userProvider, $translator);
    }

[...]

    public function doAuthenticate(Request $request): Passport
    {
        $token = $this->getTokenExtractor()->extract($request);
        if (false === $token) {
            $message = 'Unable to extract a JWT token from the request. Also, make sure to call `supports()`'
                       . ' before `authenticate()` to get a proper client error.';
            throw new LogicException($message);
        }

        try {
            if (!$payload = $this->jwtManager->parse($token)) {
                throw new InvalidTokenException('Invalid JWT Token');
            }
        } catch (JWTDecodeFailureException $e) {
            if (JWTDecodeFailureException::EXPIRED_TOKEN === $e->getReason()) {
                throw new ExpiredTokenException();
            }

            throw new InvalidTokenException('Invalid JWT Token', 0, $e);
        }

        $idClaim = $this->jwtManager->getUserIdClaim();
        if (!isset($payload[$idClaim])) {
            throw new InvalidPayloadException($idClaim);
        }

        $passport = new SelfValidatingPassport(
            new UserBadge(
                (string) $payload[$idClaim]['uid'],
                function ($userIdentifier) use ($payload) {
                    return $this->loadUser($payload, $userIdentifier);
                }
            )
        );

        $passport->setAttribute('payload', $payload);
        $passport->setAttribute('token', $token);

        return $passport;
    }

    public function loadUser(array $payload, string $identity): UserInterface
    {
        try {
            $user = (new TokenDataProcessor())
                ->extract($payload);

            return $user;
        } catch (InvalidAuthDataException $e) {
            $message = 'Authentication Failure with Credentials: ' . json_encode($payload)
                       . ' - ' . $e->getMessage();
            $this->logInfo($message);
            throw new ApiException(401, $message, $e, [], 7020);
        }
    }
}