Unable to Add Phone Number on Line Due to Region Restriction

I tried logging into the Line app, but I keep getting the error message, "Adding a phone number is not allowed in your region." I want to register using my phone number, but I’ve been struggling with this issue for a while. I’ve deleted and reinstalled the app multiple times, but nothing has worked. I’m really frustrated and need assistance to resolve this problem. Can someone please help me figure out how to successfully register with my phone number? I appreciate any support or guidance you can provide. Thank you in advance for your help!