How to create a dynamic array to pass into function that takes in `int64_t const *` type?

Question

I'm working with a codebase where there's a function with the following declaration:

int process(int64_t const *dimensions, int64_t size);

I'm working with a function that calls process and the argument that I pass into process is an array of dimensions, but the size of the array can only be determined at runtime, all the values are the same.

I need a way to write

int64_t dimensions[N] = {1};

where N is determined at runtime. Is there a possible way to do this and have it be compatible with the parameter for process?