CREATE TABLE Actual_Table(ID serial not null, Name varchar, primary key (id))

INSERT INTO Actual_Table (name) VALUES ('AHMAD');
INSERT INTO Actual_Table (name) VALUES ('MAHMOOD');

CREATE FOREIGN TABLE Foreign_Table (ID serial, name varchar) server some_server options(schema_name 'public', table_name 'Actual_Table')

INSERT INTO Foreign_Table (name) VALUES ('John');

ERROR:  duplicate key value violates unique constraint "to_copy_pkey"
DETAIL:  Key (id)=(2) already exists.
CONTEXT:  Remote SQL command: INSERT INTO public.to_copy(id, name) VALUES ($1, $2)

{
CREATE FOREIGN TABLE Foreign_Table (name varchar) server
    some_server options(schema_name 'public', table_name 'Actual_Table')
}