The following code, derived from example4_custom_functions.py errors, since the parser can't find the custom function.
def times(value):
return lambda array: list(map(lambda item: item * value, array))
query = "true and times([1, 2, 3])"
options: JsonQueryOptions = {"functions": {"times": times}}
print(jsonquery(data, query, options))
Peeking at the code, it would seem that the custom arguments passed on the higher lever evaluation are not passed to recursive evaluations, and thus the function is not found.