How to add trailing dot to hostnames using DNS Manager?

I’m configuring name servers for one of my domain according to this guide here: https://www.digitalocean.com/community/tutorials/how-to-create-vanity-or-branded-nameservers-with-digitalocean-cloud-servers

It specifically says:

(Do not forget the trailing dots)

But using the new DNS Manager UI, we can’t add trailing dot (see screenshot here: https://imgur.com/3GGVWSd)

Is there any neat trick that I’m not aware of or is it okay this way? Anybody has an idea?

Thanks!