2 Factor Authentication does't working in my ASP.NET MVC5 application.

Question

Hello Now I'm developing a web application with ASP.NET MVC5 using C#.

I wanna implement 2factor authentication with AmazonSES.
Its working well on my laptop local environment.

Then I deploy this application to Azure App Service, its not working well.
Its ok to sending Email was success.
But when sending the Authentication code to my application is failed with 500 Error Responssed.

I don't know how to resolve this problem.

Where should I have to check?