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

Results forapi2.stage.mapworks.io

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-05-11T01:03:58.758	2020-05-11T00:03:58	2020-08-09T00:03:58	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-05-11T01:03:58.639	2020-05-11T00:03:58	2020-08-09T00:03:58	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-13T06:00:31.864	2020-01-13T05:00:31	2020-04-12T05:00:31	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-01-13T06:00:31.661	2020-01-13T05:00:31	2020-04-12T05:00:31	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-10-25T06:39:49.379	2019-10-25T05:39:49	2020-01-23T05:39:49	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-10-25T06:39:49.194	2019-10-25T05:39:49	2020-01-23T05:39:49	app2.stage.mapworks.io	api2.stage.mapworks.io	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2016-11-04T05:48:51.6	2016-10-25T00:00:00	2019-11-06T23:59:59	*.stage.mapworks.io	*.stage.mapworks.io	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
2014-12-03T22:29:23.081	2014-11-07T00:00:00	2016-11-06T23:59:59	*.stage.mapworks.io	*.stage.mapworks.io	C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA