Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wb0/STM32WB05/DMAMUX/C2CR#0x0
CxCR register
DMAREQ_ID[4:0]: DMA REQuest IDentification
Selects the input DMA request. C.f. the DMAMUX table about assignments of multiplexer
inputs to resources.
https://github.com/modm-io/cmsis-svd-stm32