Use the clause final table in your insert statement, see the example below:

create table table_identity (cod1 int not null generated always as identity, cod2 int, cod3 int);

select * from final table (insert into table_identity (cod2,cod3) values (20,20),(30,30));

COD1        COD2        COD3

----------- ----------- -----------

          1          20          20

          2          30          30

  1 record(s) selected.