shell:$ nslookup -timeout=2 -retry=1 'push.duolingo.com'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
Name:	push.duolingo.com
Address: 99.84.234.81
Name:	push.duolingo.com
Address: 99.84.234.28
Name:	push.duolingo.com
Address: 99.84.234.82
Name:	push.duolingo.com
Address: 99.84.234.86