get https://api.securevan.com/v4/bulkImportMappingTypes
This endpoint returns all the available ways you can map your file columns and values to accepted models that can be imported during a bulk import operation.
This information lets you know what can be imported during your operation, what are the characteristics of those fields and their columns, which columns have a predefined list of possible data, etc.
With this information, you can build your request payload to POST /bulkImportJobs
endpoint to map some information directly from your uploaded file, hardcode some information as static, map your uploaded data to other values, or make whatever mappings are necessary to create your import.