Try KeePass. There's .NET implementation for Windows, there're few cross-platform C++ implementations for Linux and macOS, there are integrations with browser, there are mobile clients and you can configure sync as you like. For example I'm using KeePass on Windows desktop, synchronize it to my WebDAV server and then synchronize it with KeePassium iOS app. It works well and I control every single bit of it (I don't use browser extension because I think that it's too dangerous to let all my passwords to be accessible by something running in browser, but it's possible if you don't care). Simpler option for synchronization is dropbox which is popular among many users and works just as well.