can't change postgres varchar type to integer

[debu99]

Generated DDL Statement (generated at 2023-02-03T12:40:07+08:00):
create table "demoTbl" ("id" character varying (12), "title" text not null, primary key ("id"))

Generated DDL Statement (generated at 2023-02-03T13:44:30+08:00):
alter table "demoTbl" alter column "id" type integer

And the table is no data yet.

{"level":"error","msg":"ERROR: column \"id\" cannot be cast automatically to type integer (SQLSTATE 42804)"}
Executing query "alter table \"demoTbl\" alter column \"id\" type integer"
{"level":"error","msg":"ERROR: column \"id\" cannot be cast automatically to type integer (SQLSTATE 42804)"}
Executing query "alter table \"demoTbl\" alter column \"id\" type integer"
{"level":"error","msg":"ERROR: column \"id\" cannot be cast automatically to type integer (SQLSTATE 42804)"}
Executing query "alter table \"demoTbl\" alter column \"id\" type integer"
{"level":"error","msg":"ERROR: column \"id\" cannot be cast automatically to type integer (SQLSTATE 42804)"}