Publishing a finished site on a custom domain

As I have finished up my first site in webflow, I wanted to publish it on a custom owned domain. I am on the Lite account plan and when I tried publishing the site on a custom domain I found out that there is another fee of 16 euros/month for publishing it.
My question being if that 16 euros per month is required for every site I want to publish to a custom domain or is it a one time fee ?

Thank you in advance !

Yes that fee is for hosting. It will be applied to all new sites you want to publish to a custom domain.

And it is a monthly fee or just a one time one ?

Not it is a monthly fee.

Here are some other hosting providers. So you can reference the price.