How can I use Postgres collation in Windows OS?

Question

I want to customize ICU Collation of Postgres server in my windows machine.

so I created a new collation using:

CREATE COLLATION digitslast (provider = icu, locale = 'ja-u-kr-latn-digit');

and expected as below.

ex)

# select code from table order by code collate "digitslast";

code |
-----+--
a    | ...
A    | ...
1    | ...
...  | ...

But result has the same order as the default order.

code |
-----+--
1    | ...
a    | ...
A    | ...
...  | ...

Is this possible? And is there some mistake?