VOA at border Shenzhen

I have a Canadian passport and have gotten visas for China in the past. Is it still possible to get another one at the border via Luwo if coming through Hong Kong? I will need to be in Shenzhen for a few days before returning to Hong Kong.
If possible, what sort of documentation is required now? In the past, I just went to the counter and recieved one in minutes.

Thanks.