CrawlSpider Rule not working for a link that actually exists in target site-CodePudding

I'm stuck trying to find a way to make my spider work. This is the scenario: I'm trying to find all the URLs of a specific domain that are contained in a particular target website. For this, I've defined a couple of rules so I can crawl the site and find out the links of my interest.

The thing is that it doesn't seem to work, even when I know that there are links with the proper format inside the website.

This is my spider:

from scrapy.spiders import CrawlSpider, Rule
from scrapy.linkextractors import LinkExtractor


class sp(CrawlSpider):
     name = 'sp'

     start_urls = ['https://nationalpavementexpo.com/show/floor-plan-exhibitor-list/']

     custom_settings = {
        'LOG_LEVEL': 'INFO',
        'DEPTH_LIMIT': 4
     }

    rules = (
        Rule(LinkExtractor(unique=True, allow_domains='a2zinc.net'), callback='parse_item'),
        Rule(LinkExtractor(unique=True, canonicalize=True, allow_domains = 'nationalpavementexpo.com'))
    )


    def parse_item(self, response):
        print(response.request.url)
        yield {'link':response.request.url}

So, in summary, I'm trying to find all the links from 'a2zinc.net' contained inside