If you want to log in to the Mech Arena Store with a Plarium ID, but you haven't registered one before, please do the following:
1. Start Mech Arena on your mobile and tap your avatar.
2. Open the "Connection" tab.
3. Tap "Sign in with Plarium ID".
4. Enter your email address and password and tap "Register".
In the article "What is Plarium ID?" you can find more helpful information about this ID and its benefits.