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

Results forcms.letsgo.nexsoftech.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-03-06T05:36:30.365	2019-03-06T04:36:28	2019-06-04T04:36:28	cms.letsgo.nexsoftech.com	cms.letsgo.nexsoftech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-06T05:36:29.019	2019-03-06T04:36:28	2019-06-04T04:36:28	cms.letsgo.nexsoftech.com	cms.letsgo.nexsoftech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-06T05:34:37.481	2019-03-06T04:34:36	2019-06-04T04:34:36	api.letsgosystem.com	cms.letsgo.nexsoftech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-06T05:34:36.451	2019-03-06T04:34:36	2019-06-04T04:34:36	api.letsgosystem.com	cms.letsgo.nexsoftech.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3