trying to buy regional pass online

Is it necessary to buy the Japan Rail Pass - regional - osaska hokuriku arch pass - from my country (India) before I travel to Japan,
- in that case i have two options - first - to book online via jrpass site - i am not sure whether they will deliver physical pass or not - weather physical pass is needed before hand or not - second - book via third party app - they send tickets on my mail address in india

or can I buy it when I arrive in Japan. Is it the same price?

we are intending to buy via official website of yours
can you guide what would be procedure once we buy the tickets

regards
dr paras shah