My dbms output is not displayed

I'm testing a simple output of DBMS in SQLDeveloper. I created the connection, I executed set serveroutput on to enable the DBMS outputs, but when I run my anonymous code block, in Saída do Script it displays the message

  

PL / SQL procedure completed successfully.

But in the Saída Dbms window, even with my connection already added, nothing is displayed. This is the code I am trying to execute:

BEGIN
    DBMS_OUTPUT.ENABLE(2000);
    DBMS_OUTPUT.PUT_LINE('Curso Oracle PL/SQL');
END;