You may only want to award points for orders placed on your website or in-store via Shopify POS. If this is the case, you can use order rules to prevent orders from any system or sales channel from being awarded points.
To do this, go to "Rewards > Order Rules" and setup a rule to award zero points based on "Source Name". You can enter "pos" or "web" as the value depending on which channel you'd like to suppress.
Here is an example where no points are awarded on the web:
And here is an example wher eno points are awarded on Shopify POS orders:
Here is a list of possible values you can use (although not exhaustive):
web - orders placed on your website
pos - orders created through Shopify POS
App name (PayWhirl,etc) - orders created through another app
android - orders created through android app
iphone - orders crated through iphone
integer - some apps use integers to denote source
shopify_draft_order - orders created as draft order via Shopify admin