Helllo,
Neither of my routers have a drop-down tab for DYNU Dynamic DNS, so I using the apps you have for my IMAC & my several PC's and Linux boxes.
Now I need to know WHERE do you use YOUR DNS setting as primary and/or Secondary: 1) In both routers (1 is a VPN router)
2) in Network tcpiip setting in the network properties in Windows or let it default those setting to DHCP. Note DCHP server is configured in the main TP-Link router (using Mac address to apply correct fip addresss for each PC )
3) Do I add additional DNS servers on the DNS tab, I do like using Cloudflare DNS because they are so fast (any comments here is appreciated).
4) Do i specify the default gateway or let it default
5) I have my own domain ("thejohnsonthing.biz"), what options do I choose in the DNS/Domain name tab? (Or just in the system properties (computer name) tab? I know I do not have it set right, for instance I open a cmd prompt and run 'nslookup' and look below for the output:

C:\Users\kjsys>nslookup ns1.dynu.com
Server: UnKnown
Address: 192.168.0.1

Non-authoritative answer:
Name: ns1.dynu.com.thejohnsonthing.biz
Address: 181.215.172.48

See the issue---it attached my suffix of "thejohnsonthing.biz" at the end of the name I was looking up. HOW DO I FIX THAT in my windows (11) network settings:
- Do I add my Domain Name where it says "DNS Suffix for this connection" and then ALSO
- Click the button to "Register this connections address in DNS" (Since this is suppose to be Dynamic DNS, but I am not sure of those details.

Please help me out with these specific details, I am well versed in Windows and Linux server configuration, so these details will help tremendously.
Any further information or screenshots needed just let me know.

Thanks again,
Kenneth Johnson
kjsys1@gmail.com