OK thanks for the tip.
Firefox, F12, debugger
API error: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data
e https://tw.arkadi.one/static/js/client.js:2
p https://tw.arkadi.one/static/js/client.js:2
C https://tw.arkadi.one/static/js/client.js:2
w https://tw.arkadi.one/static/js/client.js:2
y https://tw.arkadi.one/static/js/client.js:2
s https://tw.arkadi.one/static/js/client.js:2
Caddy log
{"level":"error","ts":1692060935.893172,"logger":"http.log.access.log0","msg":"handled request","request":{"remote_ip":"49.159.84.13","remote_port":"41462","client_ip":"IP_REDACTED","proto":"HTTP/2.0","method":"POST","host":"tw.arkadi.one","uri":"/api/v3/user/register","headers":{"Referer":["https://tw.arkadi.one/setup"],"Cookie":[],"Content-Type":["application/json"],"Accept-Encoding":["gzip, deflate, br"],"Dnt":["1"],"Te":["trailers"],"User-Agent":["Mozilla/5.0 (Windows NT 10.0; rv:109.0) Gecko/20100101 Firefox/116.0"],"Origin":["https://tw.arkadi.one"],"Sec-Fetch-Dest":["empty"],"Content-Length":["112"],"Accept-Language":["en-CA,en-US;q=0.7,en;q=0.3"],"Sec-Fetch-Mode":["cors"],"Sec-Fetch-Site":["same-origin"],"Accept":["*/*"]},"tls":{"resumed":false,"version":772,"cipher_suite":4865,"proto":"h2","server_name":"tw.arkadi.one"}},"bytes_read":0,"user_id":"","duration":0.002207562,"size":0,"status":502,"resp_headers":{"Server":["Caddy"],"Alt-Svc":["h3=\":443\"; ma=2592000"]}}
I don't see anything wrong here though it says it is an error. Hmm.
EDIT: Ok one thing that could be wrong is it says the protcol is HTTP/2.0.
I noticed on the troubleshooting page of Lemmy it says
Make sure that websocket is working correctly, by checking the browser console for errors. In nginx, the following headers are important for this:
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
So, I am now searching if I can get Caddy to serve HTTP/1.1 for websockets?