If you bought a domain from Zyro, you can find it on the My domains page in your dashboard.
If you don't remember where you bought a domain from, go to the public domain database WHOIS that can show where your domain is registered and where it is pointing to via nameservers.
The nameservers also indicate where the domain's DNS zone is managed from. In the example above, the domain is registered at Hostinger but pointed to Cloudflare's servers. It means that the domain's DNS zone is managed from Cloudflare, too.
In other words, if you needed to add/remove specific DNS records (A, CNAME, MX, TXT, etc.), you would need to go to Cloudflare for that, despite the fact the domain is registered at Hostinger.
However, the nameservers themselves are changed at the platform the domain is registered at. So, if you want to point the domain elsewhere – to Zyro servers, for example – you would change the nameservers at Hostinger. Once the DNS propagation is over – your domain is fully pointing to Zyro servers, and the DNS zone is now managed from Zyro, too.