What is Nexmo API

Nexmo

Nexmo’s SMS API enables you to send and receive text messages to and from users worldwide, using simple REST APIs. Programmatically send and receive high volumes of SMS globally. Send SMS with low latency and high delivery rates. Receive SMS using local numbers.

How to integrate it with our system:

Signup a free account here https://dashboard.nexmo.com/sign-up
After signup, you can get your API key and API secret values
Copy them and paste under your website admin panel -> credentials http://hyraspace.cron24.com/admin
You can either use Test account or Paid Account.
In Test account, you are given €2 free credit. Using that you can you can send messages upto 10 destination numbers.
You can upgrade to Paid Account, for unlimited destinations.