Thank you for the quick response. I created the measurement on RIPE atlas portal. Please find the below image for reference, every time I check the Set DO bit field. I’ve also used the Rest API and the measurement looks like this,
  "af": 4,
  "query_class": "IN",
  "query_type": "RRSIG",
  "query_argument": "example.com",
  "use_macros": false,
  "description": "DNS measurement to",
  "use_probe_resolver": true,
  "resolve_on_probe": false,
  "set_nsid_bit": false,
  "protocol": "UDP",
  "udp_payload_size": 512,
  "retry": 0,
  "skip_dns_check": false,
  "include_qbuf": false,
  "include_abuf": true,
  "prepend_probe_id": false,
  "set_rd_bit": false,
  "set_do_bit": true,
  "set_cd_bit": false,
  "timeout": 5000,
  "type": "dns"