You are borrowing a great deal of trouble. Businesses exist to make money. They want you to spend your money. The customer is always right, never more so than in an internet day and age when a single negative online review can trigger an avalanche of other negative online reviews which can put them out of business.
Act like you are doing business, as if you have purchased SN somewhere else before, and they will conduct themselves like a business. But act suspicious, as if you, the customer, has to justify and explain what you are purchasing and why, then they will start asking questions.
Is wild game hunted in Pakistan? Then you should be good to go. If any explanation is asked for, just tell them you need to cure some meat for preservation from a kill you've been given by a hunter friend, since pre packaged curing salts are unreliable (which is true).
Botulism is far deadlier and more widespread than SN itself. Using SN to CTB is an inherently negligible use of that chemical (since people who use SN to CTB tend to die out for some reason - the only time suicide threatened to become an epidemic anywhere was when a hundred million Japanese were preparing to die before Hiroshima and Nagasaki in 1945).
Go someplace to buy SN which is not your first choice, in an area away from where you live. Then, if you fail, the experience you gain may teach you how to succeed in buying SN from some other business.
