It seems like Docify doesn’t have a setting to paste the sign-in code manually.
This page’s URL has a URL after the beginning https://vscode.dev/redirect?state= part. You can copy everything that comes after that part and URL decode it here (you have to click on “URL Decode” a couple of times). Then you got an URL that begins with cursor://aic.docify... and you can open that URL in the browser to redirect to Cursor. That should usually work, but unfortunately, it doesn’t for me. I’m still not logged in after that.
I think you should ask the devs of Docify to add a setting to paste in the auth code manually.