location ^~ /_ {
        proxy_http_version 1.1;
        proxy_pass http://yeastar/;
        proxy_cookie_path / /_/;
        proxy_buffering off;
        sub_filter 'src="../' 'src="/_/';
        sub_filter "src='../" "src='/_/";
        sub_filter 'href="../' 'href="/_/';
        sub_filter "href='../" "href='/_/";
        sub_filter '/cgi/' '/_/cgi/';
        sub_filter '../html/' '/_/html/';
        sub_filter '/html/' '/_/html/';
        sub_filter './js/' '/_/js/';
        sub_filter 'html/guialert.html' '/_/html/guialert.html';
        sub_filter 'path = /' 'path = /_/';
        sub_filter_types text/html text/css text/javascript application/javascript;
        sub_filter_once off;
    }