JWT Authentification doesn't work

I'm trying to use JWT Authentification but i'm receiving 401 unauthorized erro

My configuration in sg_config.yml is

basic_internal_auth_domain: 
    enabled: true
    order: 4
    http_authenticator:
      type: basic
      challenge: true
    authentication_backend:
      type: intern

.......

jwt_auth_domain:
    enabled: true
    order: 0
    http_authenticator:
    type: jwt
    challenge: true
    config:
  signing_key: "base64 encoded key"
  jwt_header: "Authorization"
  jwt_url_parameter: null
  subject_key: null
  roles_key: null

In my request i added Authentication header with the Bearer as mentioned in the official documentation of JSON web tokens

Is there anything I missed ? thank you in advance