The common take on this issue is that it’s not worth risking your website by buying links from shady networks or submitting it to tons of free directories.

But if you find business directories related to your niche, which maintain high-quality editorial control, there's probably nothing wrong with a link from them. 

As a first step, you can analyze your competitors’ backlinks with the help of Ahrefs Site Explorer and see which directories they use (if any).

You might want to check our guide on resource page link building - https://ahrefs.com/blog/resource-page-link-building/