Is that safe to put public IP directly on Virtual Router/ System VMs?

[Netlynker]

Hi,

I looked at the deployment architecture from document and it said to have
public IP addresses on Virtaul Router/System VMs.

Is that recommended setup?

How safe will it be to expose Virtaul Router/ System VMs directly to
internet?

Any recommendation is welcomed.

Thanks in advance,
Netlynker