AXFR is not supported by AWS Route 53, Google Cloud DNS, Azure, Rackspace, Hetzner, Bunny, Alibaba Cloud DNS, No-IP, nor Tencent.

It is supported by Akamai Edge DNS, Oracle Cloud, enterprise Cloudflare accounts, IBM NS1 Connect, ClouDNS, CloudFloorDNS, and DNS Made Easy.

Almost no mainstream existing provider you’re migrating from would support AXFR from Bunny’s servers. But yes, AXFR would be the ideal solution in a perfect world.