There are a few choices.
You can create a shortcut (Windows), script or desktop file (Linux). This is probably the easiest method, and works outside on the internet browser.
But as you talked about bookmarks, I am assuming you want to edit directly in your browser. You can host an instance of OnlyOffice Community Edition, and use that as an editor, and save the direct link to service with the appropriate arguments in the URL to recall the file.
I’m surprised they didn’t do it sooner.