Use iPad as ‘required iPhone’ for Apple Watch

I’m part of a family sharing group, and I have an iPad, an Apple Watch, and no phone. My Apple Watch has some apps I’d like to use, such as Spotify, that say “Requires iPhone” in the App Store. That’s probably there because you can’t sign in through the watch, but you CAN sign in through an iPad. Even so, it still requires an iPhone. Is there a way I can make my iPad count as an iPhone?