nginx configuration domain and ip

I'm have a problem with nginx: I want to create one server to ip address (its dynamic) and another to domain (I'm using Dynamic DNS).

How can I specify listen blocks, when ip is dynamic?

P.S. My config for domain name should stay as now:

server_name ~^(?P<sub>.+)\.top\.tld$ ~^(?P<sub>.+)\.top2\.tld$ top.tld top2.tld;

Found solution with default_server:

server {
    listen      80 default_server;
    listen      [::]:80 default_server;
    listen      443 ssl http2 default_server;
    listen      [::]:443 ssl http2 default_server;
    ...
}
server {
    listen      80;
    listen      [::]:80;
    server_name ~^(?P<sub>.+)\.top\.tld$ ~^(?P<sub>.+)\.top2\.tld$ top.tld top2.tld;
    rewrite     ^ https://$host$request_uri? permanent;
}
server {
    listen      443 ssl http2;
    listen      [::]:443 ssl http2;
    server_name ~^(?P<sub>.+)\.top\.tld$ ~^(?P<sub>.+)\.top2\.tld$ top.tld top2.tld;
    ...
}