You'll need a single DNS request, known as a "bootstrap" request. Your ISP will see a single DNS request to Google or Cloudflare or whatever, then everything after that will just look like normal https traffic.

That said, if your ISP is blocking and denying ALL dns requests for some reason (making the bootstrap request impossible), then you could still define the address locally. At that point, though, the ISP is likely blocking the IP addresses, too, so resolving the address is a bit moot.