If you wanna get an abuse address, resolve to the IP and query RIPE for the abuse mail. Every RIPE member needs to specify an abuse address and what they specify is the source of truth for their AS. No need to query a crowdsourced hearsay service.
I did not know of this service until now, so any correct result it has for any of my domains is a matter of coincidence.
I've used it for decades and don't recall a time whereby a hit has not been accurate, whereas abuse contacts listed on RIPE and all of the other registries are hit and miss, if they exist.
In addition anyone who has listed their domains there probably knows what they're doing, and won't demand a CAPTCHA, an essay or an account to report abuse.
I did not know of this service until now, so any correct result it has for any of my domains is a matter of coincidence.