My Zap doesn't trigger when my RSS feed is updated.

I am using a Zap to post content from an RSS feed to a Facebook page whenever the RSS feed gets updated, the Zap works fine when I run it manually, but the problem is that I don’t know how it should run automatically once the RSS feed gets updated

The RSS XML I’m using is very simple, so why the Zap doesn’t work automatically when the RSS gets updated, and how does it check if the RSS is updated or not?

<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"
    xmlns:content="http://purl.org/rss/1.0/modules/content/"
    xmlns:wfw="http://wellformedweb.org/CommentAPI/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:atom="http://www.w3.org/2005/Atom"
    xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
    xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
    >

    <channel>
        <title>Title goes here</title>
        <atom:link href="https://www.rss-link-goes-here/feed.xml" rel="self" type="application/rss+xml" />
        <link>https://www.website-link-goes-here</link>
        <description>Simple description</description>
        <lastBuildDate>Wed, 30 Mar 2022 16:00:00 +0000</lastBuildDate>
        <language>en-US</language>
        <sy:updatePeriod>
        hourly    </sy:updatePeriod>
        <sy:updateFrequency>
        1    </sy:updateFrequency>
        <generator>https://www.website-link-goes-here</generator>

        <image>
            <url>https://www.website-link-goes-here/feed.png</url>
            <title>Item title goes here</title>
            <link>https://www.website-link-goes-here/item.png</link>
            <width>32</width>
            <height>32</height>
        </image> 
        
        <item>
            <title>Image title goes here</title>
            <link>https://www.website-link-goes-here/image.png</link>
        </item>

    </channel>
</rss>