How to require array of items

[akshare]

I need to check that file[] and title[] are not empty.

Once I set required, I get Body does not match schema for content-type \"multipart\/form-data\"
If i remove "required", upload works correctly.

requestBody:
  required: true
  content:
    multipart/form-data:
      schema:
        required:
          - 'file[]'
          - 'title[]'
        properties:
          'file[]':
            type: array
            items:
              type: string
              format: binary
          'title[]':
            type: array
            items:
              type: string
        type: object

I have also tried this, but same results as above.

requestBody:
  required: true
  content:
    multipart/form-data:
      schema:
        required:
          - 'file'
          - 'title'
        properties:
          'file':
            type: array
            items:
              type: string
              format: binary
          'title':
            type: array
            items:
              type: string
        type: object