GoDaddy really lived up to its bad reputation and recently changed their API rules. The rules are simple: either you own 10 (or 50) domains, you pay $20/month, or you don’t get the API. I personally didn’t get any communication, and this broke my DDNS setup. I am clearly not the only one judging from what I found online. A company this big gating an API behind such a steep price… So I will repeat what many people said before me (being right): don’t. use. GoDaddy.
That’s a very interesting gotcha. They don’t seem to support address ranges either. Unless once you add the whitelist the requests still work from any address (their documentation is ambiguous). This is even more confusing.