Dragon Raja Global

I started to play this on my friend’s phone (android, and she allowed me to play Dragon Raja on her phone). I connected my account to Google. And I decided to download Dragon Raja on my phone (iPhone). After I downloaded it, I opened Dragon Raja, and unfortunately there’s no “Sign in with Google”. Is there a way how to solve this problem so that I can play my account that’s connected to Google?

If there’s no way, well, I hope the developers will make an update where we’re able to connect our account to Google on iPhone...