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

Results forecho1.minorhacks.dev

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-02-21T05:03:24.731	2021-02-21T04:03:24	2021-05-22T04:03:24	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2021-02-21T05:03:24.55	2021-02-21T04:03:24	2021-05-22T04:03:24	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2021-02-21T04:50:06.925	2021-02-21T03:50:06	2021-05-22T03:50:06	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2021-02-21T04:50:06.231	2021-02-21T03:50:06	2021-05-22T03:50:06	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2021-02-14T07:09:37.008	2021-02-14T06:09:36	2021-05-15T06:09:36	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2021-02-14T07:09:36.914	2021-02-14T06:09:36	2021-05-15T06:09:36	echo1.minorhacks.dev	echo1.minorhacks.dev	C=US, O=Let's Encrypt, CN=R3
2020-07-02T22:13:44.993	2020-07-02T21:13:44	2020-09-30T21:13:44	*.minorhacks.dev	*.minorhacks.dev	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-07-02T22:13:44.825	2020-07-02T21:13:44	2020-09-30T21:13:44	*.minorhacks.dev	*.minorhacks.dev	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3