Magento 2 Custom Shipping Method Extension supports REST APIs for data synchronizing. You can the details in the link below.
REST API
Here comes the list of REST APIs that our Magento 2 Custom Shipping Method extension supports.
Magento 2 Custom Shipping Method REST API Support
Notes:
Below is the explanation of the APIs' code.
1. Enable
| 0 | Disabled | |
| 1 | Admin | |
| 2 | Frontend | |
| 3 | Both Admin and Frontend | |
2. Type
| None | |
| O | Per Order |
| I | Per Item |
3. Store_id
store_id = 0 => Allow Store View
4. Applicable_countries
| 0 | All | |
| 1 | SPECIFIC_COUNTRY | |
| 2 | SPECIFIC_AREA | |