How to avoid duplicate records in database when using Automapper DTO to Entity

Question

I am trying to CREATE or UPDATE multiple Payment for a single Order. I would like to update the record if it exists in the database(Primary Key Value is not the default value), and I would like the record to be created if it doesn't exist in the database. For the moment, when I'm doing the creation, the Mapping adds a new order, by Payment, adds a necessary Lines and also adds the Product Item and the Wallet even if they already exist.

I use the ReverseMap() in all the DTO objects. here is an illustration

conf.CreateMap<Payment, PaymentDTO>()
            .ForMember(dest => dest.Amount, opt => opt.MapFrom(src => src.Amount))
            .ForMember(dest => dest.C_Order, opt => opt.MapFrom(src => src.C_Order))
            .ForMember(dest => dest.C_Wallet, opt => opt.MapFrom(src => src.C_Wallet))
            .ForMember(dest => dest.DateOf, opt => opt.MapFrom(src => src.DateOf))
            .ForMember(dest => dest.ID, opt => opt.MapFrom(src => src.ID))
            .ForMember(dest => dest.Order, opt => opt.MapFrom(src => src.Billing_Invoice))
            .ForMember(dest => dest.Wallet, opt => opt.MapFrom(src => src.CashWallet))
           .ReverseMap();

same logic is implement in OrderDTO, WalletDTO and so on. How to tell AutoMapper not to create new record when this record do exists in the database ? in the controller action, I tried to attach children to the context as follow _context.Wallets.Attach(model.wallet); but nothing seems to be working

here is the database diagram