This is either a bug on Adalo’s side or something you’re setting up wrong on your side, although I think it is a bug or issue right now because I did see some other posts about this earlier today.
Here: mustafa.ns.cloudflare.com is a DNS server for the domain cardmix.co. I’m requesting the CNAME record for cardmix.co directly from this server and receive that this server couldn’t be found.
Also: when I analyse the traffic, I see that the answer for request cardmix.co is 301 REDIRECT to www.cardmix.co: