Example in "42.8. Transaction Management" doesn't work for PostgreSQL v 12.7

Hi,

When the first example of the
https://www.postgresql.org/docs/12/plpgsql-transactions.html:

*--run before:*
*--create table test1(a int);*

*CREATE PROCEDURE transaction_test1()*
*LANGUAGE plpgsql*
*AS $$*
*BEGIN*
* FOR i IN 0..9 LOOP*
* INSERT INTO test1 (a) VALUES (i);*
* IF i % 2 = 0 THEN*
* COMMIT;*
* ELSE*
* ROLLBACK;*
* END IF;*
* END LOOP;*
*END;*
*$$;*

CALL transaction_test1();

The CALL fails with error:

*ERROR: invalid transaction termination*
*CONTEXT: PL/pgSQL function transaction_test1() line 6 at COMMIT*
*SQL state: 2D000*

The exact version of PostgreSQL: *PostgreSQL 12.7 (Ubuntu
12.7-0ubuntu0.20.04.1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
9.3.0-17ubuntu1~20.04) 9.3.0, 64-bit*

Regards,
Vladimir

P.S. Generally, I need the option to execute commit/rollback inside a loop
, is there a way?