老师，按照你的方法我安装了lua模块后检查了nginx配置语法出现nginx: [emerg] unknown directive “content_by_lua_file” in /usr/local/nginx/conf/nginx.conf:50这个报错

server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   html;
            index  index.html index.htm;
        }
	
	location /hello {
        default_type 'text/plain';
        content_by_lua_file 'ngx.say("hello, lua")';
    	}

	location /myip {
            default_type 'text/plain';
            content_by_lua '
            clientIP = ngx.req.get_headers()["x_forwarded_for"]
            ngx.say("IP:",clientIP)
            ';
    	}

	location / {
            default_type "text/html"; 
            content_by_lua_file /usr/local/nginx/conf/dep.lua;
            #add_after_body "$http_x_forwarded_for";
        }
        #
        location @server{
            proxy_pass http://127.0.0.1:9090;
        }
        
        location @server_test{
            proxy_pass http://127.0.0.1:8080;
        }