Generic DDNS Settings Help

I'm trying to get a self-hosted DDNS service up and running (it's RFC 2136 compliant)... and I am now running into the issue that it's very hard to interpret the servers update information to Fortinet's method of updating.

I've searched for and found some information out there... but it's just not clear to me as to how to parse out the information to the correct spots.

Here's the general information for requesting updates from the server I'm using:

https://<DDNS Address>:<Password>@<DDNS Server name>/nic/update

It also provides a username and a password for the system to use.

I found the following page on configuring this in the CLI:  https://kb.fortinet.com/kb/documentLink.do?externalID=FD33695

Which basically gives the following commands:

config system ddns
edit 1
set monitor-interface "wan"
set ddns-server genericDDNS
set ddns-domain "samplezone.no-ip.info"
set ddns-server-ip <sample IP>
set ddns-zone "samplezone"
set ddns-ttl 60
set ddns-auth tsig
set ddns-keyname "key123"
set ddns-key 'ENC MjAxMnSODyLuDX10HUlzN1aQf37Mnd8kbaunEADCqgL/HOJ0iEZYD
jD0PR5geYikgGEQipQhUXzTp9NYrqb1xY3hQ5mNNYqoNf7bZINK/Q6a0K5JrROpXVtgHKs
='

next
end

So far the way I've interpreted this information is as follows:

config system ddns
edit 1
set monitor-interface "wan"
set ddns-server genericDDNS
set ddns-domain "<DDNS Server name>"
set ddns-server-ip <Server IP Address>
set ddns-zone "<DDNS Address>"
set ddns-ttl 60
set ddns-auth tsig
set ddns-keyname "<UserName>"
set ddns-key '<Password hashed>'

next
end

I've also been tempted to utilize other server methods of setting up (like setting it to dyndns.org), but am unsure if it is hard coded to hit that services servers instead of accepting the server I set.

Thanks in advance for any assistance.