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

Results forapi.staging.cluster.migom.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-06-03T02:44:02.653	2020-06-03T01:44:02	2020-09-01T01:44:02	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-03T02:44:02.438	2020-06-03T01:44:02	2020-09-01T01:44:02	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-03T00:31:23.389	2020-06-02T23:31:23	2020-08-31T23:31:23	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-03T00:31:23.22	2020-06-02T23:31:23	2020-08-31T23:31:23	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-02T15:19:52.713	2020-06-02T14:19:52	2020-08-31T14:19:52	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-02T15:19:52.561	2020-06-02T14:19:52	2020-08-31T14:19:52	api.staging.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-05-29T13:18:06.499	2020-05-29T12:18:06	2020-08-27T12:18:06	le-17957389.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-05-29T13:18:06.281	2020-05-29T12:18:06	2020-08-27T12:18:06	le-17957389.cluster.migom.com	api.staging.cluster.migom.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3