(B) Add API project

Clinics.Backend/API/API.csproj

+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.7.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Application\Application.csproj" />
+    <ProjectReference Include="..\Domain\Domain.csproj" />
+    <ProjectReference Include="..\Persistence\Persistence.csproj" />
+    <ProjectReference Include="..\Presentation\Presentation.csproj" />
+  </ItemGroup>
+
+</Project>

Clinics.Backend/API/API.http

+@API_HostAddress = http://localhost:5276
+
+# GET {{API_HostAddress}}/weatherforecast/
+# Accept: application/json
+
+###

Clinics.Backend/API/Program.cs

+var builder = WebApplication.CreateBuilder(args);
+
+// Add services to the container.
+
+builder.Services.AddControllers()
+    .AddApplicationPart(typeof(Presentation.AssemblyReference).Assembly);
+
+// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+    app.UseSwagger();
+    app.UseSwaggerUI();
+}
+
+app.UseHttpsRedirection();
+
+app.UseAuthorization();
+
+app.MapControllers();
+
+app.Run();

Clinics.Backend/API/Properties/launchSettings.json

+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:61331",
+      "sslPort": 44332
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5276",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "https://localhost:7046;http://localhost:5276",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

Clinics.Backend/API/appsettings.Development.json

+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

Clinics.Backend/API/appsettings.json

+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}