Video Doorbell 4 charging

Set up a ring system for my mother, including a Ring Video Doorbell 4. As there was no obvious power source nearby, I opted for the solar panel that iis integrated with the doorbell. It sits around the outside of the bell.I realised there was some risk as I am in the Uk and south facing is best for these. the position is much more South West/West South West.Unfortunately, this did not seem to charge the doorbell. What is worse is that the doorbell went from 100% to 19% in 5 days. I realise there may have been motion capture setting issues and did remove as many potential motion events as possible.However, I have come to the conclusion that it would be better if I could ensure a continuous charge. I can run a long lead to a power source but am not sure if this doorbell would even support that.From what I can gather, a usb can only connect to the back of the battery pack and that would be inside the case. The charging connection for the solar panel is 2 tightening screws on the back of the doorbell case which I assume I would need to use.Is this possible and, given I am in the uk and need a 5m cable to reach a UK plug socket, what would people recommend for accessories to do this?****** UpdateI see now that there is a Plug-In Adapter that looks suitable. Is that what I should be purchasing?