“Plug and play” preamp not working at all

Hey everyone, I’m having a bit of trouble with some equipment ti just got. I have the Shure SM7B and it’s been very nice, only thing is, the audio is SUPER quiet. I use this mic for Discord calls all the time and people can barely hear me most of the time. So I did a little research and figured I needed to get a preamp. I got the StudioMan DPM1 preamp on amazon and i plugged it in to see… nothing. Literally zero input detected from the mic when i plug it in. Am I using it wrong? Am I using it for the wrong mic? Should I do something else to boost my audio? I could really use the help.