Function nt_allocate_virtual_memory 

pub fn nt_allocate_virtual_memory(
    handle: HANDLE,
    base_address: *mut PVOID,
    zero_bits: usize,
    size: *mut usize,
    allocation_type: u32,
    protection: u32,
) -> i32

Available on x86-64 only.

Dynamically calls NtAllocateVirtualMemory.

It will return the NTSTATUS value returned by the call.