I want to add one extra field in type, but it’s on production

No, if you're just adding a field, your data will be safe. The CLI will also warn you for destructive changes, so you have nothing to worry about.

@agartha thank you. For default value is

@migrationValue("test")

?

@agartha can I create the unique string field, which will be not required, but unique if presents?

I'm not sure if unique fields need to be required, but you can easily test that

thank you