def _inject_default_for_maybe_annotations(
    cls: builtins.type[T], annotations: dict[str, Any]
) -> None:
    """Inject `= None` for fields with `Maybe` annotations and no default value."""
    for name, annotation in annotations.copy().items():
        if _annotation_is_maybe(annotation) and not hasattr(cls, name):
            setattr(cls, name, None)
Inject `= None` for fields with `Maybe` annotations and no default value.
strawberry/types/object_type.py