create empty file

Program.cs

@@ -13,6 +13,15 @@ if (!app.Environment.IsDevelopment())
     app.UseHsts();
 }
 
+// create file
+var configuration = app.Services.GetService<IConfiguration>();
+var filePath = configuration["ContentFilePath"];
+
+if (!File.Exists(filePath))
+{
+    File.WriteAllText(filePath, string.Empty);
+}
+
 app.UseHttpsRedirection();
 app.UseStaticFiles();