So when I installed my amcrest doorbell it came with a small component that jumps across the doorbell chime leads so that the push button and camera unit get continuous power. I didn’t open it up but I assume it’s just a small resistor. Here’s the link to the manual. It’s got some info on wiring too that might help.
https://drive.google.com/open?id=1JmduLOXZetxixoFjSTGhf5IbDlLUHB7M
So when I installed my amcrest doorbell it came with a small component that jumps across the doorbell chime leads so that the push button and camera unit get continuous power. I didn’t open it up but I assume it’s just a small resistor. Here’s the link to the manual. It’s got some info on wiring too that might help. https://drive.google.com/open?id=1JmduLOXZetxixoFjSTGhf5IbDlLUHB7M