RTC Battery buying link

I need to buy the RTC battery for the vicharak axon board.It support the 1mm JST two pin connector.But in the online store ther is available for the 1.25 JST two pin connector.Can kindly anyone share the buying link of the RTC battery for the Vicharak Axon?

How to work on it.And activate rtc battery in the vicharak axon.

It’s already configured in linux kernel, RTC is working on i2c0; you can directly use it using the hwclock Linux command utility to set and get time.

https://docs.vicharak.in/vicharak_sbcs/axon/peripherals/rtc/