INSERT INTO tb1 (name) VALUES ("a") 
   RETURNING id INTO :bind_var1;

scott@ORA92> -- create table:
scott@ORA92> create table tb1
  2    (ID int,
  3  	name varchar(20))
  4  /

Table created.

scott@ORA92> -- create sequence:
scott@ORA92> create sequence tb1_id_seq
  2  /

Sequence created.

scott@ORA92> -- create trigger:
scott@ORA92> create or replace trigger tb1_bir
  2    before insert on tb1
  3    for each row
  4  begin
  5    select tb1_id_seq.nextval into :new.id from dual;
  6  end tb1_bir;
  7  /

Trigger created.

scott@ORA92> show errors
No errors.

scott@ORA92> -- declare bind variable:
scott@ORA92> VARIABLE bind_var1 NUMBER

scott@ORA92> -- insert:
scott@ORA92> INSERT INTO tb1 (name) VALUES ('a') RETURNING id INTO :bind_var1
  2  /

1 row created.

scott@ORA92> -- view value of bind_var1 that contains value of tb1.id:
scott@ORA92> PRINT bind_var1

 BIND_VAR1
----------
         1

scott@ORA92> -- results of insert:
scott@ORA92> select * from tb1
  2  /

        ID NAME
---------- --------------------
         1 a

scott@ORA92> 

CREATE OR REPLACE PROCEDURE insert_tb1
  (p_name IN  tb1.name%TYPE,
   p_id   OUT tb1.id%TYPE)
AS
BEGIN
  INSERT INTO tb1 (name) VALUES (p_name) RETURNING id INTO p_id;
END insert_tb1;
/

VARIABLE some_variable NUMBER
EXECUTE insert_tbl ('a', :some_variable)
PRINT some_variable