I guess facebook and instagram aren't the best platforms for targeting business owners. The best platform in your case is linkedin and moreover, you can build a great marketing campaign in this social network, because all the tools for this are in the internet. You should try linkedin, there you can find companies (even small ones) where will be only business owners actually. You should connect trial version of linkedin professional sales navigator and it will help you a lot. Nevertheless, you should do the same in facebook, by filtering companies which you need. It's kinda difficult, however it's possible to sort out in it.