NTP problem of Jetson Nano

I would like to ask u a question that I followed the instruction Enabling PPS on Jetson Nano and I got pp0 for kernel and pps1 from the externel part. I also get the GPSD from my GPS module.

But the problem is the NTP part, I tried to get the NTP server but I can just get the result:

My ntp.conf is:

Could you give me some advice about it? Thanks!