Ring door bell transformer

Hi all,

Setting up a ring doorbell. Current wired doorbell doesn’t seem to have enough power..

What kind of transformer would I need to get? When I tap the two wires for the ring together they still chime but the ring doesn’t read them when all connected up.

It’s a small thing but like the idea of trickle charging the ring.

It’s a ring doorbell 3 plus.. have wired it up from the current set up.

Any other info needed? When I check the chime box from old doorbell it wired to mains and then into what I think is transformer and out to doorbell.

Thanks.