SQL> create or replace
  2  package MY_PKG is
  3    procedure P;
  4  end;
  5  /

Package created.

SQL>
SQL> create or replace
  2  package body MY_PKG is
  3    procedure P is
  4      x varchar2(100);
  5    begin
  6      select 'mysecretcode' into x from dual;
  7    end;
  8  end;
  9  /

Package body created.

SQL>
SQL>
SQL> grant execute on my_pkg to scott;

Grant succeeded.

SQL>
SQL> conn scott/tiger@pdb21a
Connected.
SQL> select text
  2  from all_source
  3  where name = 'MY_PKG';

TEXT
--------------------------------------------------
package MY_PKG is
  procedure P;
end;