tunnel server error: status=404, body=404 page not found

[dfang]

client log

2020-07-19 22:02:49 [tunnel-client] DEBUG    Trying to connect to "117.50.99.221:80" with identifier "123456789"
2020-07-19 22:02:49 [tunnel-client] DEBUG    CONNECT to "http://117.50.99.221:80/_controlPath/"
2020-07-19 22:02:49 [tunnel-client] DEBUG    Writing request to TCP: &{Method:CONNECT URL:http://117.50.99.221:80/_controlPath/ Proto:HTTP/1.1 ProtoMajor:1 ProtoMinor:1 Header:map[X-Ktunnel-Identifier:[123456789]] Body:<nil> GetBody:<nil> ContentLength:0 TransferEncoding:[] Close:false Host:117.50.99.221:80 Form:map[] PostForm:map[] MultipartForm:<nil> Trailer:map[] RemoteAddr: RequestURI: TLS:<nil> Cancel:<nil> Response:<nil> ctx:0xc0000ae010}
2020-07-19 22:02:49 [tunnel-client] DEBUG    Reading response from TCP
2020-07-19 22:02:49 [tunnel-client] DEBUG    client connect error: tunnel server error: status=404, body=404 page not found

on server, 80 port is listenning

sudo lsof -i :80
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
main    16252 root    3u  IPv6 345290      0t0  TCP *:http (LISTEN)
main    16252 root    4u  IPv6 345293      0t0  TCP 10-9-158-214:http->183.17.59.5:10355 (ESTABLISHED)
main    16252 root    8u  IPv6 345295      0t0  TCP 10-9-158-214:http->183.17.59.5:10661 (ESTABLISHED)
main    16252 root    9u  IPv6 345300      0t0  TCP 10-9-158-214:http->183.17.59.5:10673 (ESTABLISHED)
main    16252 root   10u  IPv6 345305      0t0  TCP 10-9-158-214:http->183.17.59.5:8397 (ESTABLISHED)
main    16252 root   11u  IPv6 345313      0t0  TCP 10-9-158-214:http->183.17.59.5:10197 (ESTABLISHED)
main    16252 root   12u  IPv6 345338      0t0  TCP 10-9-158-214:http->183.17.59.5:10218 (ESTABLISHED)
main    16252 root   13u  IPv6 345369      0t0  TCP 10-9-158-214:http->183.17.59.5:9558 (ESTABLISHED)
main    16252 root   14u  IPv6 345411      0t0  TCP 10-9-158-214:http->183.17.59.5:9483 (ESTABLISHED)
main    16252 root   15u  IPv6 345837      0t0  TCP 10-9-158-214:http->183.17.59.5:11937 (ESTABLISHED)
main    16252 root   16u  IPv6 345943      0t0  TCP 10-9-158-214:http->183.17.59.5:8659 (ESTABLISHED)
main    16252 root   17u  IPv6 346148      0t0  TCP 10-9-158-214:http->183.17.59.5:8249 (ESTABLISHED)
main    16252 root   18u  IPv6 346370      0t0  TCP 10-9-158-214:http->183.17.59.5:9753 (ESTABLISHED)
sudo lsof -i :80
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
main    16252 root    3u  IPv6 345290      0t0  TCP *:http (LISTEN)
main    16252 root    4u  IPv6 345293      0t0  TCP 10-9-158-214:http->183.17.59.5:10355 (ESTABLISHED)
main    16252 root    8u  IPv6 345295      0t0  TCP 10-9-158-214:http->183.17.59.5:10661 (ESTABLISHED)
main    16252 root    9u  IPv6 345300      0t0  TCP 10-9-158-214:http->183.17.59.5:10673 (ESTABLISHED)
main    16252 root   10u  IPv6 345305      0t0  TCP 10-9-158-214:http->183.17.59.5:8397 (ESTABLISHED)
main    16252 root   11u  IPv6 345313      0t0  TCP 10-9-158-214:http->183.17.59.5:10197 (ESTABLISHED)
main    16252 root   12u  IPv6 345338      0t0  TCP 10-9-158-214:http->183.17.59.5:10218 (ESTABLISHED)
main    16252 root   13u  IPv6 345369      0t0  TCP 10-9-158-214:http->183.17.59.5:9558 (ESTABLISHED)
main    16252 root   14u  IPv6 345411      0t0  TCP 10-9-158-214:http->183.17.59.5:9483 (ESTABLISHED)
main    16252 root   15u  IPv6 345837      0t0  TCP 10-9-158-214:http->183.17.59.5:11937 (ESTABLISHED)
main    16252 root   16u  IPv6 345943      0t0  TCP 10-9-158-214:http->183.17.59.5:8659 (ESTABLISHED)
main    16252 root   17u  IPv6 346148      0t0  TCP 10-9-158-214:http->183.17.59.5:8249 (ESTABLISHED)
main    16252 root   18u  IPv6 346370      0t0  TCP 10-9-158-214:http->183.17.59.5:9753 (ESTABLISHED)

but

curl localhost:80/_controlPath/
404 page not found