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

Results fordevelop.tastingplanner.com

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2020-08-06T11:29:23.494	2020-08-06T10:29:23	2020-11-04T10:29:23	verhalensprokkelaar.nl	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-08-06T11:29:23.326	2020-08-06T10:29:23	2020-11-04T10:29:23	verhalensprokkelaar.nl	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-07T21:29:01.956	2020-06-07T20:29:01	2020-09-05T20:29:01	www.quelamontagne.fr	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-07T21:29:01.725	2020-06-07T20:29:01	2020-09-05T20:29:01	www.quelamontagne.fr	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-07T19:02:41.051	2020-06-07T18:02:40	2020-09-05T18:02:40	develop.tastingplanner.com	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2020-06-07T19:02:40.893	2020-06-07T18:02:40	2020-09-05T18:02:40	develop.tastingplanner.com	develop.tastingplanner.com	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3