Every form that in Webflow has as action (webflow default) as in the following screen
Will be converted as a Netlify Form.
Naturally if you are not hosting on Netlify, using Netlify forms is pretty useless. In this case you have different options:
Select a third party forms provider from this list;
Create a script on your server, probably your hosting provider supports running PHP scripts;
For both options, you just have to set the correct action in your Webflow Form.