Please use the caddy fmt command to clean up your Caddyfile syntax, it’s hard to follow because the indentation is not correct.
reverse_proxy /ombi:3579
Don’t put / there. It’ll try to make a request to a hostname /ombi which is not a thing.
reverse_proxy /* jfa-go:8056
Same here, remove /* as I explained earlier.
curl makes an HTTP request, so you use the same address as you would in a browser.
ping is not HTTP, it’s just raw TCP packets with a command asking to have the message sent back. Read about it here: Communication Networks/Ping - Wikibooks, open books for an open world
This means that you weren’t able to make a connection to your Caddy server. Did you expose ports 80 and 443 to the internet? That domain resolves to this IP for me:
$ host stream.movies4you.digital
stream.movies4you.digital has address 69.246.201.79
You might want to read this:
Also, FYI you could avoid a lot of the repetition in your Caddyfile by using snippets.