настя воду намутила, я исправила

Bank/BankBusinessLogics/BankBusinessLogics.csproj

@@ -8,6 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Logging" Version="7.0.0" />
+    <PackageReference Include="System.Drawing.Common" Version="7.0.0" />
   </ItemGroup>
 
   <ItemGroup>

Bank/BankContracts/BindingModels/ClientBindingModel.cs

@@ -3,10 +3,12 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using BankDataModels;
+using BankDataModels.HelperInterfaces;
 
 namespace BankContracts.BindingModels
 {
-    internal class ClientBindingModel : IClientModel 
+    public class ClientBindingModel : IClientModel
     {
         public string FirstName { get; set; } = string.Empty;
 

Bank/BankContracts/BindingModels/PaymentBindingModel.cs

@@ -3,10 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using BankDataModels;
 
 namespace BankContracts.BindingModels
 {
-    internal class PaymentBindingModel : IPaymentModel
+    public class PaymentBindingModel : IPaymentModel
     {
         public DateOnly Date { get; set; } = DateOnly.FromDateTime(DateTime.Now);
 

Bank/BankContracts/BindingModels/PurchaseBindingModel.cs

@@ -3,10 +3,12 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using BankDataModels;
+using BankDataModels.ProxyModels;
 
 namespace BankContracts.BindingModels
 {
-    internal class PurchaseBindingModel : IPurchaseModel
+    public class PurchaseBindingModel : IPurchaseModel
     {
         public int ClientId { get; set; }
         public DateOnly DatePurchase { get; set; }

Bank/BankContracts/SearchModels/ClientSearchModel.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace BankContracts.SearchModels
 {
-    internal class ClientSearchModel
+    public class ClientSearchModel
     {
         public int? Id { get; set; }
         public string? PhoneNumber { get; set; }

Bank/BankContracts/SearchModels/CostSearchModel.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+
 namespace BankContracts.SearchModels
 {
     public class CostSearchModel

Bank/BankContracts/SearchModels/EmployeeSearchModel.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+
 namespace BankContracts.SearchModels
 {
     public class EmployeeSearchModel

Bank/BankContracts/SearchModels/OperationSearchModel.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+
 namespace BankContracts.SearchModels
 {
     public class OperationSearchModel

Bank/BankContracts/SearchModels/PaymentSearchModel.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace BankContracts.SearchModels
 {
-    internal class PaymentSearchModel
+    public class PaymentSearchModel
     {
         public int? Id { get; set; }
         public int? OperationId { get; set; }

Bank/BankContracts/SearchModels/PurchaseSearchModel.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace BankContracts.SearchModels
 {
-    internal class PurchaseSearchModel
+    public class PurchaseSearchModel
     {
         public int? Id { get; set; }
         public DateOnly? DateTo { get; set; }

Bank/BankDataModels/IClientModel.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace BankDataModels
 {
-    internal class IClientModel : IId
+    public interface IClientModel : IId
     {
         string Email { get; }
         string FirstName { get; }

Bank/BankDataModels/IPaymentModel.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace BankDataModels
 {
-    internal class IPaymentModel : IId
+    public interface IPaymentModel : IId
     {
         double PaidPrice { get; }
         DateOnly Date { get; }

Bank/BankDataModels/IPurchaseModel.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace BankDataModels
 {
-    internal class IPurchaseModel : IId
+    public interface IPurchaseModel : IId
     {
         int ClientId { get; }
         DateOnly DatePurchase { get; }

Bank/BankDataModels/ProxyModels/CostByPurchaseModel.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace BankDataModels.ProxyModels
 {
-    internal class CostByPurchaseModel : IId
+    public class CostByPurchaseModel : IId
     {
         public virtual int Id { get; set; }
         public virtual int CostId { get; set; }

Bank/BankDataModels/ProxyModels/OperationByPurchaseModel.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace BankDataModels.ProxyModels
 {
-    internal class OperationByPurchaseModel : IId
+    public class OperationByPurchaseModel : IId
     {
         public virtual int Id { get; set; }
         public virtual int OperationId { get; set; }