MIT app inventor BLUETOOTH DON'T SHOW NAME

intento conectar mi dispositivo con app que tiene BLUETOOTH cliente y al tratar de conectar no aparecen las direcciones MAC, los nombres. indica el siguiente error: error 503 unable to conect, is the divice turned on?

Welcome to the community. Could you please post a screenshot of your blocks in order to get help. Also since this is your first visit have a look at