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

Non-authoritative answer:
Name:	app.doctorsim.com
Address: 104.20.9.3
Name:	app.doctorsim.com
Address: 104.20.8.3
Name:	app.doctorsim.com
Address: 2606:4700:10::6814:803
Name:	app.doctorsim.com
Address: 2606:4700:10::6814:903