It appears you are not setting the input parameters required for the API, these are MetricsContext APIs and requires MetricsContext to be set as input parameter to enumerate.
Although nvperf_host.h headers misses to list it as “[in]” in the comment section.
In your cupti package refer code
samples\extensions\src\profilerhost_util\List.cpp for metric enumeration.
samples\extensions\src\profilerhost_util\Metric.cpp for metric configuration.
samples\extensions\src\profilerhost_util\Eval.cpp for metric evaluation.