i have nginx format but not show any result line

[paopao2019]

log_format  main  '$request_time $upstream_response_time $remote_addr - $upstream_addr [$time_local] '
                  '$host "$request" $status $bytes_sent '
                  '"$http_referer" "$http_user_agent" "$gzip_ratio" "$http_x_forwarded_for" - "$server_addr"';

/usr/local/python3.9/bin/ngxtop -f main -l /var/log/nginx/access.log --no-follow