I think it’s not a feature of like, available just on click
On higher paid plans, there is an option to block Open Proxies:
Helpful topic here:
However, you can subscribe a 3rd party VPN IP database and query it your page to block traffics.
I’d suggest you to purchase some monthly trial VPN like Namecheap offers, connect withing each of the countries, check the IP and look for the ASN, make a list of ASNs and block them using IP Access Rules at Cloudflare dashboard.
Therefore, make sure to whitelist Facebook IP or ASN.
However, this doesn’t make you more secure, as far as Facbook scraping tool can be abused and misused against your website. Kindly, search on Google for those kind of topics for more related information.
I am afraid we cannot block everyone who’s using a VPN as this might be a difficult one, but you can block the most that way, if so.
We can create Firewall Rules and block the TOR users, at least.
Nevertheless, consider blocking some of the known “bad user-agents”, “crawlers” or “bad ASNs” using below posts: