According to the specs here, there is an M.2 slot for an SSD.
Hello, I am using Inspiron 3280 AIO, serial number:   I want to upgrade ram & storage. The device came with core i3-8th gen. Ram: 4GB DDR4 2400 MHz & 1tb HDD. I know that there is an extra slot for ram upgradation. My question is, any extra slot for SSD? Or should I remove the HDD and put a SATA SSD in its place? 
Extra slot for SSD?