Aside from maximizing your profile's appeal (making sure you have good pictures, making sure your first picture is the best, writing a bio that is interesting or at least not off-putting), I don't know that there's much you can do. There's any number of reasons they might not be matching back ranging from genuinely uninterested to inactive profile.

From what I've heard from people who pay the fee to see who swiped right on them, those match numbers they show are usually from people outside of your age / distance range.

Also, if you're in an area heavily affected by the pandemic, I wouldn't sweat the disappointing return. I started up some profiles again in March / April-ish when I heard people were using dating apps to meet others, but that was NOT my experience. I got maybe a third or a fourth of the number of matches I had gotten in past iterations, and of those who matched, they were much less likely to message, and of those who messaged, it was much less likely to go anywhere and just resulted in boring in-app pen pal conversations that one of us would eventually give up on.