The process is increasingly convoluted to figure out. I'm still clinging on to their 1Password 6 license and it's now broken in Safari on Catalina. Life goes on.
It has detected Dropbox sync out-of-the-box and kept working with existing settings. But it won't refill passwords, unless I either subscribe or buy a license (a pop-up forces me to do so). I'm curious why you're not seeing the same behavior.