Access token request page expired

Question

I am sending a request to get the box token access. I receive a 200 code but the response is a html that says "The page you were viewing has expired".

the request:

access_token_params = {
      grant_type: 'authorization_code',
      code: params[:code],
      client_id: "id",
      client_secret: "secret"
    }

    box_ressources[:token].post(params: access_token_params) { |response, request, result, &block|
      check_request_success(response, "send_access_token")
      logger.info(response.to_str)
      set_token
}