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

Results for*.dev.firstplay.io

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2021-01-27T00:23:16.529	2021-01-27T00:00:00	2022-02-24T23:59:59	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon
2021-01-27T00:23:16.529	2021-01-27T00:00:00	2022-02-24T23:59:59	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon
2020-03-05T11:58:18.553	2020-02-27T00:00:00	2021-03-27T12:00:00	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon
2020-03-05T11:58:18.553	2020-02-27T00:00:00	2021-03-27T12:00:00	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon
2020-02-27T08:56:23.083	2020-02-27T00:00:00	2021-03-27T12:00:00	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon
2020-02-27T08:56:23.083	2020-02-27T00:00:00	2021-03-27T12:00:00	firstplay.io	*.dev.firstplay.io	C=US, O=Amazon, OU=Server CA 1B, CN=Amazon