I figured it was something like that.
dig @1.1.1.1 _dns.resolver.arpa SVCB ;; ANSWER SECTION: _dns.resolver.arpa. 300 IN SVCB 1 one.one.one.one. alpn="h2,h3" port=443 ipv4hint=1.1.1.1,1.0.0.1 ipv6hint=2606:4700:4700::1111,2606:4700:4700::1001 key7="/dns-query{?dns}" _dns.resolver.arpa. 300 IN SVCB 2 one.one.one.one. alpn="dot" port=853 ipv4hint=1.1.1.1,1.0.0.1 ipv6hint=2606:4700:4700::1111,2606:4700:4700::1001
I figured it was something like that.