No-allocation copying from Span<byte> into the unmanaged memory (IntPtr)

I have preallocated Span<byte> and unmanaged memory pointed by IntPtr and I want to copy contents from the Span into unmanaged memory. I would like to avoid additional allocations and unsafe context.

The task looks pretty simple, but I found that Marshal.Copy only supports copying from byte[] and can't process Span in any way. So, with Marshal.Copy I ended up with a following code, which envolves an intermediate allocation of byte[]

    Span<byte> src = GetSpan();
    IntPtr dst = GetUnmanagedMemoryPointer();
    byte[] tmp = src.ToArray();
    Marshal.Copy(tmp, 0, dst, src.Length);

The other way I found is to wrap the unmanaged memory with the Span, but this envolves unsafe

    Span<byte> src = GetSpan();
    IntPtr dst = GetUnmanagedMemoryPointer();
    
    Span<byte> dstSpan;
    unsafe
    {
        dstSpan = new Span<byte>(dst.ToPointer(), src.Length);
    }
    src.CopyTo(dstSpan);
    

Both variants works, but both are non-perfect. So, can we perform direct copy from Span into unmanaged memory without unsafe context and/or additional intermediate allocations?