Yes, if you were doing it on your computer you'd do the EQ in Equalizer APO, making sure to have the APO installed for the Bathys, which will appear as a sound card.
If doing on an Android phone, you could use Wavelet (converting the EQ using a graph tool like Crinacle's or squig.link) or an app like Poweramp EQ, or individual players like USB Audio Player Pro.
The onboard EQ in the Bathys app is too limited to input Oratory's EQ. It would be nice if it could, I have a few BT devices that can do this, but it's a very limited fixed 5 band GEQ and you don't have enough control to do it.
The Bathys does seem quite well tuned stock though, if you did want to have a go with the built-in GEQ the main thing would be filling in the 900Hz dip, which you'd need to use the 1kHz slider to do. You'd probably also want to bump up 4kHz a little, and leave the rest alone.
Subjectively, reviewers have said the 900Hz dip is not particularly problematic. Maybe adds to a sense of soundstage. While the rest of it looks really pretty good, the bass is almost exactly Harman stock, not bleeding into the mids, and then you might just want to up the upper mids a bit.
Personally, with a BT headphone like this, I would see if I could get it sounding good just using the app EQ. Because it's just so convenient having the EQ actually on the headphone, so you just turn it on and go and don't have to mess with swapping EQ profiles on your source. You could compare with Oratory's full PEQ on a source device, to try to tweak it closer. If comparing make sure you remember to not have both on at the same time.
