Google Search Console 404 Error Report For /1000 URLs Spike

Like others, we’ve recently seen a spike in issues where lots of our client sites have large numbers of 404 URL errors in GSC, as explained here – https://www.seroundtable.com/google-search-console-404-error-report-1000-urls-36728.html

We are looking to create a redirect rule to move any URL ending in //1000 to simply redirect to the same URL without that element and trailing slash.

Attempt for source URL was this: ^(.*)//1000$

And target URL was this: /$1/

But it doesn’t hold the site URL within that redirect. What’s the correct entries for source + target URLs for the redirect rule here please?

The page I need help with: [log in to see the link]