You mean for the sequence the identity uses? No. Oracle Database generates one for you.

Though you can use a sequence as a default which is similar to an identity:

create sequence s;
create table t (
  x int generated as identity,
  y int default s.nextval
);

select column_name, data_default from user_tab_cols
where  table_name = 'T';

COLUMN_NAME  DATA_DEFAULT                     
X            "CHRIS"."ISEQ$$_197251".nextval  
Y            "CHRIS"."S"."NEXTVAL"   

PS - you need to save your LiveSQL script before you can share it!