When in Clickatell, you'll be prompted to sign in to Shopify and the app.
When you , there are two required fields you have to add in the Clickatell Portal:
Give a name to your integration so you can easily identify it.
This can be anything (max. 30 characters).
Your Host Name is unique and is the first part of your URL when logged into Shopify, up until the .com/.
Copy this part of the URL over to the Clickatell Portal as the Host Name.
Example hostname: https://clickatell.myshopify.com/