can not use resty redis

[logan2013]

when i try to connect to the ws server（ws://ip:8081/ws）, it raise error

2021/03/25 00:20:34 [info] 16392#16392: *1 client 113.92.35.59 closed keepalive connection

my nginx.conf content

worker_processes 2;
user root;

events {
    worker_connections 1024;
}

error_log logs/error.log debug;

http {
    server {
        listen 8081 reuseport;
        location /ws {
                        access_by_lua_block {
                                local ngx = ngx
                                local redis = require("resty.redis")
                                ngx.log(ngx.INFO, "access stage")
                                local red = redis:new()
                                local ok, err = red:connect("127.0.0.1", 6379)
                                if not ok then
                                ngx.exit(ngx.HTTP_UNAUTHORIZED)
                                end
                        }
        }

    }
}

[logan2013]

@agentzh please help, thanks