Is there a way to add a subject alternate name when setting the acme_domain field?

I use a cname to point to the acme_domain that is used to deploy Pritunl and would like to included that when Lets Encrypt makes the cert request.

The Lets Encrypt domain option can include a list of comma separated domain names.

Do you have an example? Every time I try that it always concatenates them into a single string and validation fails.

Just for reference vpn.stud in this case would be a dynamic url that gets generated and vpn.stage would be the cname. No matter how I enter them in the Domain field they always get joined together. Pretty sure the CLI command does the same thing.

[ancient-thunder-9461][2024-04-11 10:04:52,082][ERROR] Failed to get LetsEncrypt cert
Traceback (most recent call last):
File “/usr/lib/pritunl/usr/lib/python3.9/site-packages/pritunl/handlers/”, line 1112, in settings_put
File “/usr/lib/pritunl/usr/lib/python3.9/site-packages/pritunl/”, line 73, in update_acme_cert
cert = get_acme_cert(, csr, cmdline)
File “/usr/lib/pritunl/usr/lib/python3.9/site-packages/pritunl/”, line 45, in get_acme_cert
certificate = acmetiny.get_crt(
File “/usr/lib/pritunl/usr/lib/python3.9/site-packages/pritunl/”, line 138, in get_crt
raise ValueError(“Challenge did not pass for {0}: {1}”.format(domain, authorization))
ValueError: Challenge did not pass for {‘identifier’: {‘type’: ‘dns’, ‘value’: ‘’}, ‘status’: ‘invalid’, ‘expires’: ‘2024-04-18T10:04:49Z’, ‘challenges’: [{‘type’: ‘http-01’, ‘status’: ‘invalid’, ‘error’: {‘type’: ‘urn:ietf:params:acme:error:dns’, ‘detail’: ‘DNS problem: NXDOMAIN looking up A for - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for - check that a DNS record exists for this domain’, ‘status’: 400}, ‘url’: ‘’, ‘token’: ‘Z8vbt84uFGkr8huoVMikxHsAn15xntiODgXSmqIv7so’, ‘validated’: ‘2024-04-11T10:04:50Z’}]}
acme_domain = “

Actually for Pritunl it is only one domain. Pritunl Zero and Pritunl Cloud have support for multiple domains but not the VPN server.