A website with 2 languages. How to copy the new site and do the subdomain of languages No. 2

I am in the process of doing a website with 2 languages. I have finished the Danish version, and now I will start with the English version. All pages on the English site must be exactly the same as the Danish site. How do I copy the Danish site so that I can start the English version in Webflow and only change the text? And how do I do this so that the English site becomes subdomain from the Danish site?