Unable to Access My Line Account on New Phone – Region Error and Lost Stickers

I’ve been using Line for eight years, but now I can’t log into my account after changing my phone. I tried using the QR code to sign in, but when I attempt to register with my phone number, it says, “your number is not valid in this region.” How is this even possible? After years of using the app, I’m suddenly unable to register on my new device. Additionally, all the stickers I received as gifts have disappeared. This is incredibly frustrating, and I need help resolving this issue as soon as possible. Please assist me in recovering my account and restoring my missing stickers.