Magento 2 Store Credit Extension supports both REST and GraphQL APIs. Please refer to the two links below for details of each API.
REST API
Here comes the list of Magento 2 Store Credit extension's REST API.
Magento 2 Store Credit REST API Support
GraphQL API
This link directs you to the list of GraphQL APIs that Magento 2 Store Credit extension supports.
Magento 2 Store Credit GraphQL API Support
* NOTE:
Types of Store Credit are explained in this table:
| Value | Label |
| 1 | Refund |
| 2 | Used in order |
| 3 | Update |
| 4 | Revert |