How to point subdomain to app on server

Thanks all, most especially the MDG team and the developers of Meteor-Up. It’s breezy using it, very awesome. I have 2 apps successfully deployed to a server. The main app is to run at https://oltega.com and the other to run on a subdomain of the main app as this - https://courses.oltega.com. The first app works perfectly while the other on the subdomain is always unreachable if I try to access it using https. If I use http it returns "This website is temporarily unavailable, please try again later." I have the domain on GoDaddy while the host server is on another hosting company. I have followed all known tutorials but haven’t gotten it to work. This has been over 2 days and have not yet displayed the app. I was thinking it was propagation time but now I think not like that again.
This is my subdomain config on Godaddy

Seems to be working now!

You just need to update your letsencrypt certificate to include the subdomain now.

Thanks. @herteby. It was a wrong config I did earlier on Godaddy. It’s working now, as you spotted the encryption did not work on the subdomain. You just need to update your letsencrypt certificate to include the subdomain now. How do I do this?

Right now I can see that your certificate covers “oltega.com” and “www.oltega.com”, so just use whatever method you used to register those to register a new certificate that also covers “courses.oltega.com”.