yield scrapy.Request(url, callback=self.parse_house_contents)
for next_page in response.css('.pager .br3.brc8::attr(href)'):
    url = response.urljoin(next_page.extract())
yield scrapy.Request(url, self.parse)

def parse_house_contents(self, response):
    property_id = re.search('ID(\\w+)\\.', response.url).group(1)
phone_url = 'https://olx.pt/ajax/misc/contact/phone/%s/' % property_id
yield scrapy.Request(phone_url, callback=self.parse_phone)

def parse_phone(self, response):
    phone_number = json.loads(response.body)['value']
print(phone_number)
Scrapy + Splash + ScrapyJS