Refer to Table 7-2. Module operation in low power modes in the KW41 reference manual for the watchdog module operation in the different power modes.
There is no software component that facilitates the use of an external watchdog.
The watchdog is disabled at startup in most of the wireless examples.
To understand the watchdog operation in KW41 you can refer to the Computer operating properly (COP) driver example project in <SDK>\boards\frdmkw41z\driver_examples\cop\. Additionally, you can refer to the 3.4.11.2 COP watchdog operation chapter in the KW41 reference manual.