Button to trigger specific action in form

I have forms and workflows built in another application that can facilitate this function and it works a treat. Now coming to Nintex, i would like to be able to do something comparable.

Having buttons in a form that could initiate a test email at a click and or trigger an API - for example:

Scenarion: User has a form and needs to click a button to receive a passcode from an SMS provider that contains a specific code generated for that session.

1) User enters details in the form + phone number

2) Presses the API SMS button.

3) Triggers action to send a specific code that is configured, utilises noJSON or JSON web services action OR potentially SMTP call to Message Media or the like, to allow entry to the next page for user to complete all details (noting could contain PIA/PII questions and or Doctors details - hence the security layer).

4) Code is 1-time use only for that session

Please refer to case: Nintex Support Case #00706004