seeed xiao How to use nrf52840 external 32mhz clock?

I am building a bluetooth system using seeed nrf52840
I am using bluefruit library
But it seems that there are only USE_LFXO and USE_LFRC in clock options
As far as I know, USE_LFXO and USE_LFRC use 32.768khz crystal as source
I have 32mhz crystal installed, can’t I use this crystal as source?
Thank you