Search Console sees old urls

I have tens of thousands of deleted urls but Search Console detects them. I’ve read through the grapevine that Cloudflare may be slow to see changes. What if he doesn’t see the changes at all? This would explain a lot.

Can you help me?

A few seconds.

If you have your old URLs properly redirected to the new ones (in case the content is still there, but under a new URL), or returning 404s for URLs that no longer exist, you should be fine as far as SEO goes. Now, do not expect Googlebot to “forget” your old URLs. My oldest domain was created when Chrome didn’t exist. For a brief period it had a blog and a store, both closed after a few weeks. To this day, over a decade later, Googlebot still occasionally requests these old URLs.

Some of the examples below may help you setup the redirects your website needs.