I use PostgreSQL copy command to make a csv file.
COPY (select * from table) from '/tmp/123456.csv' with csv header encoding 'UTF8';
this command is ok
But I want to make file with ANSI encoding, because I want to open it in Microsoft Excel
COPY (select * from table) from '/tmp/123456.csv' with csv header encoding 'ANSI';
this command can't make csv file
Since you seem to be on Windows, maybe you want to use one of the Windows encodings, for example WIN1252
for western European languages.