Creating a app for a zigbee device

Dear Forum People!

I’am trying to create a simple zigbee app.
I have a Heiman motion sensor (https://www.zigbee2mqtt.io/devices/SMHM-I1.html ) i try to config to the app. I’am also updated to the firmware version 5.0 to use the SDK 3.0 . So the app will be working in the future :wink:
I also read the de development page and trying to do my best to understand the technical matter.
So this is the reason i’am trying reach out to you!

On a zigbee device it has different feature like batterie capacity… or device information. Whats is the best way to retrieve those features? is that with the debug mode ? or is there another way?
Also how is the link relation with a cluster of a device? and an endpoint of a device?
Maybe are this stupid questions … But if i know this (simple) solution… the other devices are no issue’s anymore and i can contribute to the community.

I also have created a github what i done already. Maybe the code looks like an amateur, but i’am trying my best.

Please advise what to do.
Greetz,
Jeffrey de Jong.

For technical question the slack channel is also a great source of help