Make a phone call using dotnet

Question

Hi, 

I implemented a security mechanism for our web api, using Microsoft Owin Oauth2

As part of the security mechanism, when the user connects to the system, a security code should be sent to him, which he will have to enter to confirm login to the system.

So basically I need a really simple feature of dialing the user's phone and then one of the two: either read his login code in Hebrew, or the phone number he dials will be the code itself (such as the security implemented in Netflix)

I searched a lot, tried Twilio and found that they do not support Hebrew,

I tried Plivo and got stuck in a section that requires purchasing a subscription, purchasing a phone number, etc., even just to try out their capabilities.

 Do anybody have a direction to direct me?