OP, that looks an awful lot like a pc fan connector socket. Maybe these will work? https://www.amazon.com/Letool-Electrical-Female-Connector-Cables/dp/B07FP2FCYC/ref=asc\_df\_B07FP2FCYC/?tag=hyprod-20&linkCode=df0&hvadid=459486453992&hvpos=&hvnetw=g&hvrand=632626444505927358&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033015&hvtargid=pla-930783811610&psc=1
10 Pairs 1.25 mm JST 2 Pin Micro Electrical Male and Female Connector Plug with 80mm Wire Cables https://www.amazon.com/dp/B07FP2FCYC
I used the following battery and JST connector. You will also need some kapton tape to keep it secure.