Well... Create space for black voices on the platform for a start. You’ve done it for LGBTQ and BL/GL. Creation of perhaps a BIPOC “genre” may also be a good step, or encouraging writers who write from their own marginalised experiences to submit for featuring opportunities. Encourage use of tags more, perhaps, to indicate this kind of information and make the search work to actually pick this up properly.
There are interview spots that you guys sometimes do. Get some black voices on those, and yes, promote their work. But also move beyond that and speak to them about the issues that also are still faced in posting/creating/publishing work.
Encourage sensitive conversations around diversity, both on the forums and through content put out by Tapas itself. Educate your community.
Do a social media call that asks the black community what they want from Tapas. Just being real, there aren’t many on the forums because the forums aren’t that comfortable for many marginalised people. You’ll get a better response on Twitter/Insta/FB.
Dedicate lists on the front page to elevating black voices throughout the year. Black History Month aside, there’s also Africa Day, and other identities that can be pulled in and celebrated more in that way.
Hire someone who is able to look at your business model and assess where the bottlenecks are that are stopping black creators come forward.
Actively search for black and BIPOC voices to elevate, and if they’re not on Tapas yet, find out why and reach out to some creators to bring them on board.
Just some ideas.