To connect Big Business to Shopify you need to log into your Shopify Admin to create a new Custom App and get an API Key and Password.
Custom App settings let you control access to Shopify
API Key and Password let Big Business connect
This Solution tells you how to generate custom app credentials for Shopify. (6631)
To create Custom App credentials for Shopify:
1. On your Shopify Admin, click Settings
2. Click the link to Apps and Sales Channels
3. Click the button to Develop Apps
4. Click the button to Create An App
5. Enter a Title, like "Big Business 14"
6. Click to Configure Admin API Scopes
7. For Orders click Write_Orders and Read_Orders
8. Click Save
Shopify will generate an API Key and Password that you enter into Big Business.