The network is called LinkedIn. If you’re not yet on LinkedIn, you need to go there. Search for people and search for the company name in the search bar on the LinkedIn site. Perhaps filter your results on your environment so that they are not too numerous to sort. You will see a list of people on LinkedIn working in the company for which you applied. I hope one of them is in your network.
Maybe they are not at the first level, so you do not have direct access to their email address, but use the LinkedIn tools to contact them via people you know. If you have a friend who has a friend who works for the company, it’s the proxy to know someone who works there, and if the friend of the friend would not want to pass your resume or your name So, you have improved your chances of being considered for the job at a giant pace.