Looking for a free online web design tool

I am looking for something similar to Pastel but instead of placing comments, I would like to implement changes to the UI. Right now I am focusing on WP but if there´s a tool that can handle multiple CMS that would be ideal.

I want the ability to easily customize the Ui and design of a page (homepage, service, page, product page, etc.) and share it with potential clients and showcase the difference between the old and new version.

I am also aware of Figma but, can I import the URL of a live page into Figma? I don´t know

So, Is there something like this?