Engage like hell and treat it like more than a full time job. I emailed nearly 150 companies with a partnership/pr request , maybe more. The majority of them said no but once my following count got higher I at least got more than just a rejection email. I am okay with just getting products and posting for now because I can use them to make a portfolio to pitch to other brands. I use the OnBrand platform, put an email that is specifically for pr/ job things in my bio.