Not able to Purchase Max Annual Subscription

I have A Mac book air (2020). I do not have any other ios/apple device. But when i am trying to purchase Margin note 4 Annual subscription in my country (1299 INR) it shows following notification . I can click on lifetime subscription (4999 INR) but not on annual or half yearly subscription. It abruptly stops after i click “ok” and takes me to “Unlock Max Lifetime Forever Page”.