Cloudflare cheatsheet

curl -X PUT "https://api.cloudflare.com/client/v4/zones/<ZONE_IDENTIFIER>/dns_records/<RECORD_ID>" \
  -H "X-Auth-Email: user@example.com" \
  -H "X-Auth-Key: YOUR-AUTH-TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"type":"A","name":"example.com","content":"127.0.0.1","ttl":{},"proxied":false}'

Authenticate to Cloudflare API using user@example.com email and YOUR-AUTH-TOKEN token, to update a ZONE_IDENTIFIER record with RECORD_ID.