Internet connection is required error iPhone 12 Pro – Botim - Video and Voice Calls Review

I got a new iPhone 12 Pro and downloaded the app. I’m connected to the internet from where I’m writing this review. However, when I try to add a phone number, BOTIM says “an internet connection is required to complete this action”. Duh! How do I proceed?
Review by Mel4629 on Botim - Video and Voice Calls.