The domain is now ready to be linked to the server's IP address. To create a DNS record, login into your Google Domains account.
On the left menu, select DNS and scroll to Custom resource records.
Create the following entry:
IP address: ip of your server.
The process may take a while; however, judging from experience you should be able to browse to your domain within a few minutes.
Test by entering your domain into a browser. You should see the Welcome to nginx! page.