SQL & PL/SQL :: Insert Values Fetched From Object Type Into Empty Table?

I need to insert values fetched from an object type into an empty table.

-- >> table creation:

create table ASSET
(
ASSETID NUMBER(5),
ASSETTYPE VARCHAR2(20));

-- >> created an object_type

SQL> create or replace type obj1 as object(v_ASSETID NUMBER(20),
2 v_ASSETTYPE varchar2(20));
3 /
Type created

--- >> create the package

SQL> create or replace package test_arr is
2 type nest_tab is table of obj1;
3 procedure insert_data(t_nest IN nest_tab);
4 end test_arr;
5 /

Package created

SQL> create or replace package body test_arr is
2 procedure insert_data(t_nest IN nest_tab) is
3 begin
4 for i in t_nest.first..t_nest.last loop
5 insert into asset(ASSETID,
6 ASSETTYPE) values (t_nest(i).v_ASSETID,

[code]....

-- >> a block to execute the above package:

SQL> declare
2 type ref_tab is table of obj1;
3 ref_tab1 ref_tab;
4 begin
5 ref_tab1 := ref_tab(1,'a');
6 test_arr.insert_data(ref_tab1);
7 end;
8 /

But I am getting the below error when executing the package:

ORA-06550: line 5, column 13:
PLS-00306: wrong number or types of arguments in call to 'REF_TAB'
ORA-06550: line 5, column 13:
PLS-00306: wrong number or types of arguments in call to 'REF_TAB'
ORA-06550: line 5, column 1:

[code]....