301 Redirects with .html

Hello,

I had an static site that has .html at the URL’s end.

Now I’m publishing with webflow and it doesn’t have it. I set an 301 redirect rule that says:
/blog/(.*) → /artigos/%1

But it doens’t remove the .html os the pages, it just pastes the article name after /artigos/

How can I remove it, since I have no access to the htaccess?

Thanks