University of the South Pacific, which runs the DNS servers, [1] is up.

Google's DNS server at 8.8.8.8 is having problems.

Lookup using DNS server of sonic.net, which is a normal DNS server.

    nslookup usp.ac.fj
    Server:  127.0.0.53
    Address: 127.0.0.53#53

    Non-authoritative answer:
    Name: usp.ac.fj
    Address: 144.120.141.80

Lookup with Google DNS:

    nslookup 
    > server 8.8.8.8
    Default server: 8.8.8.8
    Address: 8.8.8.8#53
    > usp.ac.fj
    Server: 8.8.8.8
    Address: 8.8.8.8#53

    ** server can't find usp.ac.fj: SERVFAIL

Checking example.com to make sure Google DNS server is live.

    > example.com
    Server:  8.8.8.8
    Address: 8.8.8.8#53

    Non-authoritative answer:
    Name: example.com
    Address: 93.184.216.34
    Name: example.com
    Address: 2606:2800:220:1:248:1893:25c8:1946

Also fails with 1.1.1.1 DNS server.

The Fiji DNS servers are unreachable, but you can get as far as a router at the University of the South Pacific. So the problem is local to there.

    traceroute 144.120.146.1
    traceroute to 144.120.146.1 (144.120.146.1), 30 hops max, 60 byte packets
    ...
     8  AARNET-PTY.edge5.London1.Level3.net (217.163.113.74)  274.795 ms  274.476 ms  273.781 ms
     9  xe-0-0-0.pe1.a.suv.aarnet.net.au (113.197.15.213)  312.534 ms  311.764 ms  311.766 ms
    10  fastethernet0-0.aarnie.usp.ac.fj (202.158.204.194)  313.356 ms  312.176 ms  312.363 ms
    11  * * *
    12  * * *

[1] https://www.usp.ac.fj/