Hello,
I checked Sync Feature with my colleagues and found out that on iOS, we have only history and bookmarks supported in Sync. Don't worry, the data should be secured on our servers and only you can access them. The solution could be to install the windows version of the browser, export passwords (from password manager settings) and import them on iOS. This means Sync will not work but at least you will have the passwords there.
Please let us know if you need any help with this.
Ondrej