curl --request POST \
  --url https://api.sanka.com/v1/public/migrations/global-japan/bootstrap \
  --header 'Authorization: Bearer <token>'

{
  "workspace_id": "<string>",
  "company_external_id_field_id": "<string>",
  "item_external_id_field_id": "<string>",
  "order_external_id_field_id": "<string>",
  "invoice_external_id_field_id": "<string>",
  "estimate_external_id_field_id": "<string>"
}