slight "boxy" sound on voice recording

[Trebor]

so there’s no easy way in Audacity to reduce the reverb?

There are De-reverb plug-in$ …

Accusonus ERA-D: Remove Noise and Reverb From Your Audio

Remove Reverb with Dialogue De-reverb in RX 7 Advanced

DeVerberate 2 - Early Reflections Filter

but IMO they’re only useful to reduce slight reverb, (your example is strong reverb).