Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/FDCAN1/FDCAN_TXEFC#0x0
EFWM=B_0x0, EFS=B_0x0
FDCAN Tx event FIFO configuration register
Event FIFO start address
Event FIFO size.
0 (B_0x0): Tx event FIFO disabled
Event FIFO watermark
0 (B_0x0): Watermark interrupt disabled
https://github.com/modm-io/cmsis-svd-stm32