To connect to Shift4Shop/3dcart follow these steps:
Log in to your Shift4Shop/3dcart Admin Dashboard
Click Modules
Search for "REST" in the search bar
4. Click Settings in the REST API
5. Click Add
6. Copy this key {key} and paste it into the corresponding field and click Save
7. Fill Source store URL
8. Fill in Target Store information and start migration by clicking' Next: Configure your migration"