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

Results forapi-uat.donefirst.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-09-03T23:25:43.694	2020-09-03T22:25:41	2020-12-02T22:25:41	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-03T23:25:42.136	2020-09-03T22:25:41	2020-12-02T22:25:41	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-02T11:09:58.165	2020-09-02T10:09:57	2020-12-01T10:09:57	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-09-02T11:09:57.82	2020-09-02T10:09:57	2020-12-01T10:09:57	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-12T10:18:02.705	2020-08-12T09:18:02	2020-11-10T09:18:02	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-12T10:18:02.501	2020-08-12T09:18:02	2020-11-10T09:18:02	api-uat.donefirst.com	api-uat.donefirst.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3