send from the UI a nested object file

Question

put('test') do
  parameter name: :params, in: :body, schema: {
    type: :object,
    properties: {
      certificate: { type: :file, in: :formData }
    },
  }
}
end

put('test nested') do
  parameter name: :params, in: :body, schema: {
    type: :object,
    properties: {
      live: {
        type: :object,
        properties: {
          certificate: { type: :file, in: :formData }
        }
      }
    },
  }
end

should I do binary or file on the type ? How can I nest in it that doesn't appear on the UI ?