Как я могу создать платежную страницу в своей платежной системе ?

I am working on an  payment system using mvc 5, And i almost finished a large part of the work such as the transfer of funds and the proportion of fees, etc.

But I'm having a problem now - the payment page for purchases from e-commerce sites,

And how a system api receives information from the customer, such as the price and account, and the name of merchant , That is, when the customer moves from the shopping cart to the payment page directly and the purchase information is converted to the payment confirmation page,
I tried to convert url information to the payment confirmation page but I did not succeed, and I hope to find help or code source  mvc5 with it and how to secure that page the transfer of this information.

public class Transaction  
    {  
        [Key]  
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]  
        public int Id { get; set; }  
  
        //foreign key of eBankingUser  
        //hear userName will be assigned because GUID may not unique   
        [Required]  
        [Display(Name="User")]  
        public string UserId { get; set; }  
  
        //foreign key of transection table  
       // [Required]  
        public string OperationNumber { get; set; }  
  
                  
        [NotMapped]  
        public string CountryName { get; set; }  
  
        [NotMapped]  
        public string CurrencyISO { get; set; }  
  
        //[Required]  
        public int? PinId { get; set; }  
   //     public int? PinCode { get; set; }  
  
        //Local amount that is inserted to transfer or recharge or top up  
        public decimal? InsertedAmount { get; set; }  
  
        //USD  
        public decimal? AmountIN { get; set; }  
  
        //USD  
        public decimal? AmountOut { get; set; }  
  
          
        public int? RatePlanId { get; set; }  
  
        public int? Status { get; set; }  
  
        public DateTime? TransactionDate { get; set; }  
  
  
        [Display(Name = "Recepient User")]  
        public string ToUser { get; set; }  
  
        public string FromUser { get; set; }  
  
        public DateTime? UpdateDate { get; set; }  
  
        public string Remarks { get; set; }  
  
        [NotMapped]  
        public string ServiceName { get; set; }  
  
  
        [Display(Name="Reference")]  
        public string ReferenceId { get; set; }  
  
        [NotMapped]  
        public bool IsCheck { get; set; }  
        public DateTime? TimeOut { get; set; }  
        public bool IsTimeOut { get; set; }  
        public int ClientId { get; set; }  
        public int VendorId { get; set; }  
        public decimal? UserBalance { get; set; }  
         
    }  
  
//Repository  
 public bool CreditTransferDbEntry(Transaction tIn, Transaction tOut, string fromUser, string toUser)  
        {  
            ITransactionRepository transaction_repo = new TransactionRepository(db);  
            using(var contextTransaction = db.Database.BeginTransaction())  
            {  
                try  
                {  
                    var fee = tren_rep.GetById(1).MRP; /*ConstMessage.ConstFee_ID;*/  
                    tOut.UserBalance = transaction_repo.UserBalanceUpdate(fromUser, -(decimal)tOut.AmountOut);  
                    transaction_repo.Add(tOut);  
                    tIn.UserBalance = transaction_repo.UserBalanceUpdate(toUser, (decimal)tOut.AmountOut - ((decimal)tOut.AmountOut * ((decimal)fee /100)));  
                    transaction_repo.Add(tIn);  
                    //UserUpdate(fromUser);  
                    //UserUpdate(toUser);  
  
                    contextTransaction.Commit();  
                    return true;  
                }  
                catch (Exception)   
                {  
                    contextTransaction.Rollback();  
                }  
            }  
              
            return false;  
        }