Nullability of type of parameter 'exception' doesn't match overridden member (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'x' of 'int VnPayCompare.Compare(string x, string y)' doesn't match implicitly implemented member 'int IComparer<string>.Compare(string? x, string? y)' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'y' of 'int VnPayCompare.Compare(string x, string y)' doesn't match implicitly implemented member 'int IComparer<string>.Compare(string? x, string? y)' (possibly because of nullability attributes).

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Non-nullable property 'UserId' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Code' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'Password' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Non-nullable property 'ConfirmPassword' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.