Hi @CodingLukas,
Welcome to the Community!
That looks like an opaque token, meaning it is one that cannot be decoded. If you are looking for a JWT Access Token to use with your own API, you will need to register your API and use its API identifier as the audience in the Auth0Client config:
audience
auth0 = await createAuth0Client({ domain: config.domain, client_id: config.clientId, audience: config.apiIdentifier });