The phrase "packet instructions" refers to the written directions or information that come with a product or package. These instructions typically explain how to use or assemble the contents of the packet. Full definition
If using glass (bean thread) noodles, soak as per packet instructions. (swoonfood.com)
Follow the box or packet instructions for cooking time. (emmafrisch.com)
In boiling water, cook these cauliflower florets for about 10 - 12 minutes till soft (or following packet instructions, if you use frozen cauliflower). (vkool.com)