Can you show what records you’ve been asked to add?
Right now, you have both a TXT and a CNAME for info.fikolki.pl, which indicates that you’ve added something incorrectly, as you can’t have both for the same name.
info.fikolki.pl. 300 IN TXT "mailerlite-domain-verification=fbb1ef77dfd0ff16e018d6ef781eb60d401eb72c"
info.fikolki.pl. 300 IN CNAME litesrv._domainkey.mlsend.com.
Yes, of course. Attached is the file authorization_cloudflare — a screenshot with the records that need to be added
and three files with what is in Cloudflare (TXT1, TXT2, CNAME).
We have the main domain fikolki.pl, which has already been authorized by MailerLite. Now we want to authorize the subdomain info.fikolki.pl.
and i have “The authorization failed”
Your screenshot from mailerlite doesn’t show this subdomain. Have you added the subdomain to them? They should offer to adds the DNS records for it automatically as well.