Scrapy: selecting dynamically-loaded content with "More" button

I'm trying to scrape content from page similar to this: https://www.newsweek.pl/nwpl_2018002_20181231. It has "More" (pl. Więcej) button at the bottom of the page, which dynamically loads next articles. Preferably I would like to use Scrapy to do the task, because my other spiders use it, but first I need all of the articles urls; so I'm trying to click() this button with Selenium as follow:

def parse_issue(self, response):
        self.logger.info('Parse function called parse_issue on {}'.format(response.url))
        self.driver.get(response.url)
        while True:
            try:
                more_button = self.driver.find_element_by_xpath('//div[@class="showMoreBtn"]')
                time.sleep(2)
                more_button.click()
                time.sleep(5)
                print('clicked.')
            except Exception as e:
                print(e)
                break
        articles_elements = self.driver.find_elements_by_xpath('.//div[@class="pure-u-1-1 pure-u-md-1-4 smallItem"]/a')
        articles_url = [element.get_attribute("href") for element in articles_elements]
        print(articles_url, response.url)

Unfortunately, as a result I only get urls of articles that are already in the source of the page. Can someone suggest me what I'm doing wrong?