Transformer Kit to use just Video Doorbell pro 2?

hi there So I have no chime nor any doorbell system in my home. I got the video door bell pro 2 ( the latest version) along with the transformer kit. But on the manual of transformer kit it says " This transformer is only for use with both a Ring doorbell and a 16-24 volt AC doorbell chime. To power a ring door bell on its own, use a Ring Plug-in Adapter." Does this mean I can't use the transformer and must use the adapter if I have no chime? Why?