Owlette question

I got the owlette from gift cards given to us @ our baby shower. I’m so excited for it but we don’t have WiFi at our place. We only use hotspots when we need to use the internet. For anyone who does have an owlette, do we NEED WiFi to see baby’s readings... I know it still alerts me if anything is wrong w/o WiFi but I’m not sure about the readings