Video Doorbell Pro 2 (wired), no existing doorbell

I just purchased a Ring Video Doorbell Pro 2 (still in its box). My home does not have an existing wired doorbell but I have easy wiring access to an indoor electrical outlet and I have a UL listed 24 VAC 300ma plug-in transformer that I can use. I would like to know if I need to use the Pro Power Kit V3 that came with the ring doorbell as I do not have an existing chime. It also now appears that I need a larger transformer as the ring doorbell instructions state 10 VA minimum and the transformer that I have only supplies 7.2VA