How to insert modal iFrame for embedded POS apps

bemissmith
Tourist
4 0 1

Hi, I am trying to insert a modal message during the point of sale specifically when the user hits the 'continue to shipping' button.  From what I've read it appears I need my app to:

  • be enabled as an embedded POS app
  • add a POS link to specify the callback url (eg. http://xxxx.ngrok.io/page_in_my_app_backend)
  • choose the app display mode to be modal
  • choose 'Edit cart' in 'Page to show link' (the only other option I have is 'order completed') 

I don't see any callbacks happening with this process and it appears to me I'm missing something since with only two options there doesn't seem to be the granularity needed to 'insert yourself anywhere in the checkout process' as the documentation suggests.

Can anyone give me any clues on what needs to be done here?  My goal is simple...

  • the user clicks on 'Continue to shipping' while checking out
  • the embedded app calls my react backend
  • the front end shows my page in the iFrame to the user.

Thanks, any help would be greatly appreciated