I have a synology NAS device that I'd like to configure to use my ddns from you. Here is the form and format they are looking for in setup:

https://ddns.provider.org/update?hostname=__HOSTNAME__&myip=__MYIP__

can you help me with this information?

Hostname: __HOSTNAME__
IPV4 address: __MYIP__
Username/Email: __USERNAME__
Password/Key: __PASSWORD__

What are the variable values for hostname and myip? I assume username is my synology login name and password is the password for that user?