Personal supplement `multipart/form-data`. File field names are fixed: `id_document_front`, `id_document_back`, `address_proof` (aligned with the checklist `code`); the optional string field `relationship_proof` (JSON text) is merged with the upload result.
| Name | Type | Description | Notes |
|---|---|---|---|
| BankId | string | ||
| IdDocumentFront | string | ID document front-side file content (multipart file field, binary/Base64) | [optional] |
| IdDocumentBack | string | ID document back-side file content (multipart file field, binary/Base64) | [optional] |
| AddressProof | string | Proof-of-address file content (multipart file field, binary/Base64) | [optional] |
| RelationshipProof | string | Optional. JSON string of relationship_proof. | [optional] |