Everything was OK until I transferred my domain from GoDaddy to Google Domains.
The site (birth2day.netlify.app) was accessible as www.birth2day.com. After the transfer is completed, I’ve logged into Google Domains and delegated name servers to point Netlify DNS (dns1.p02.nsone.net).
I thought it will be enough to point Google Domain’s name servers to Netlify. Unfortunately, the site is down for 2 days.