nginx refusing connection on port 443

[crodges]

Hello everybody,

I'm setting up a guix vps and having some trouble, mainly because I'm getting 
used to the guix way. After a few tries, I finally got a let's encrypt 
certificate and nginx configured to read it. Problem is, nginx accepts fine 
connections on port 80, but when I try 443 I get

curl: (7) Failed to connect to lambdashire.com port 443 after 5249 ms: 
Connection refused

My first thought was to open port 443 on the firewall, but I don't know how to 
do that and didn't find how to in a few configuration examples I searched. Is 
this the right approach, to open the port? If it is, can you please point me 
to some documentation so I can try to figure out myself?

First time posting. Thanks.