The option to print is only for orders that are in the correct statuses. The orders have to clear the first step to check & confirm. Only then it will proceed to second step where you are able to print documents. It varies from one platform to another:

Shopee: READY_TO_SHIP with tracking number (pick-up has to be scheduled first)

Lazada: Packed or ready_to_ship

Qoo10: Seller Confirm(3)