Should I be using a Pro Power Kit V2

Sorry new to the community group and have not found something that fully answers my questions. I have one mechanical doorbell that rings for both front and back doors. I installed a Ring Doorbell (not sure the model) hard-wired (no battery ) to the front door wires and all was good. I did the same to the back door with an older Ring doorbell that does have a battery but hardwired. Most features did not work so I assumed and read about the power. I inserted that battery and figured I would run the back door with a battery and left it hard wired. Cold get here and I am getting a critically low battery for the front that is hardwired and does not have a battery. Have tried resetting it and reinstalling it but still critical low so now it have reverted back to just ringing the old doorbell, not alerting my phone or Alexa. So 1) how can I get rid of the critical low battery and 2) does it sound like I need a Power Adapter kit? Hope I was able to explain this well. Thanks