Ask HN: Any ideas on how to reach out to startups from the non-tech domain?

I am just about to launch a productized service business. My target audience is very early-stage startups who wish to build their website, email setup, and brand-identity in a very cost-effective manner.

Most of the tech-startup folks can do these things themselves. So I am interested in reaching out to a few non-tech startups.

I tried reaching out to a few of them offline (mostly friends) and got some good early-stage orders. Now to scale it more, I want to reach out to them online.

What are my options to reach out to them? Are there any Reddit communities or Facebook groups that I should join?

Alpha Stage Link: https://www.growby.net (Just developed in 3 days)