Can Myanmar passport holder apply for visa on arrival at Hanoi to Nanning border as a tourist ?

Actually, I did apply china 3 months visa which ends oct 2016 . Now I am visiting Thailand , Cambodia, and Vietnam which are visa free for a Myanmar citizen. I am planning to visit guangzhou via hanoi - Nanning border as a tourist and I can show money or my online visa card account for my travel expenses. Could I apply for VOA? If so, how long will it take ? Thank you for reply.