Perhaps this post could be a good starting point, for how to create your own Comment-Box.
https://www.wix.com/velo/forum/community-discussion/auto-update-owner-s-picture-using-a-code
And on this site you will be able to see a little result, of how your futured comment-box, could look like…
https://russian-dima.wixsite.com/meinewebsite/autoupdate-picture
(on the very bottom of the main-site)