Email them and keep it short, make it timely (what have you accomplished recently, how is it relevant to a current event or trend) and offer to provide other pieces of the story (e.g. do you have a customer or investor who’d be willing to speak to the reporter? Do you have photos, graphics, data you could send the reporter). Offer to jump on a call and speak on the record.
One mistake I’ve seen founders make is they treat the reporters as a marketing channel. I.e they want the reporter to help them “get the word out.” That is not a reporters job. Their job is to bring their readers timely, interesting and novel stories, so your goal is to help the reporter accomplish that.