It can be anything! An apex, subdomain, or even a URL.

Results forexcel.suhail.cloudcomputer.app

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-02-04T04:18:29.653	2020-02-04T03:18:29	2020-05-04T03:18:29	excel.suhail.cloudcomputer.app	excel.suhail.cloudcomputer.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-02-04T04:18:29.529	2020-02-04T03:18:29	2020-05-04T03:18:29	excel.suhail.cloudcomputer.app	excel.suhail.cloudcomputer.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-05T08:03:15.752	2019-12-05T07:03:15	2020-03-04T07:03:15	excel.suhail.cloudcomputer.app	excel.suhail.cloudcomputer.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-05T08:03:15.635	2019-12-05T07:03:15	2020-03-04T07:03:15	excel.suhail.cloudcomputer.app	excel.suhail.cloudcomputer.app	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3