By default, Nubo creates a URL for your service, e.g. express.nubo.dev.
If you would like to create a custom domain for your service, simply select Manage Domains.
Enter your custom domain name.
Make sure to create the CNAME record with your domain provider before saving.
Now head over to your domain registrar and create a CNAME record for your domain and point it to domains.nubo.global.
You can also create a record for a subdomain. Follow the same steps at your registrar to create a CNAME record for your subdomain.