@anelem1760873, with the dispatcher module, there's no mechanism for you to find 404 pages. However, if you have nodeJS installed into your machine, you can use a custom nodeJS module tool to check through all your pages and review all 404 pages.
I have posted my solution here in the past, please have a look, https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/find-and-fix-broken-links-...
In my opinion, this tool is very useful.