Domainnameshop's API
We have an API you may use for this purpose.
Dynamic DNS from another provider
There are free and cheap services available, e.g. DynDNS.org, No-IP.com and ChangeIP.com.
In order to use such services, you have to set up a DNS pointer for your domain (e.g. www.example.com) to the address assigned by the provider.
For the domainname itself without "www" or any other prefix/subdomain, we will automatically create an ANAME record for you if you provide a DNS name. If you provide an IPv4 address, we automatically create an A record, for an IPv6 address, an AAAA record.
Alternatively, you may use www forwarding from https://example.com/
to https://www.example.com/
and let www.example.com be handled dynamically as in the example below.
CNAME created automatically
ANAME created automatically