Trouble with https issued using tailscale cert

Tailscale version
Your operating system & version macOS High Sierra Ver: 10.13.6

I’m a total newbie. This is my first attempt at running anything outside of standard mac software from the App Store.

I successfully installed tailscale with a very basic setup. I turned on ssh, magic dns (with google nameserver), services, and that’s it. I have 3 machines listed - imac, iphone, macbook pro. I can ping all of them. I can ssh all of them. I can vnc between laptop and desktop. All is good so far. My ultimate goal is to run a web server with a small home made website, probably using caddy.

I turned on https. Gave me * As per instructions I went to desktop to run tailscale cert. I am logged in as an administrator. I tried to run sudo tailscale cert - but receive a “Illegal Instruction 4” error.

Then I try to run $ /Applications/ cert
It returns an Internal Server Error invalid domain:

Next I try to run $ /Applications/ cert

It returns 500 Internal Server Error: acme.GetReg: Get “”: (what looks like IP6 addresses) :443 read: operation timed out.

When I look at the services running on the imac - I don’t have port 80 or port 443 showing.

I’m not sure what to do next. Please help!