ZCL Attributes Reporting

I am working on a zigbee Coordinator and have successfully able to perform most of the operations on the end device (thermostat which is custom developed) including read and write of multiple attributes. Now would like to receive reporting data from the end device. I have a few doubts regarding the same and any info regarding that will be highly helpful.
    1. Is it mandatory to send a bind request from coordinator to end device in order to enable reporting of a specific attribute? Or is there an alternative where the end device can do local binding without a bind request from Coordinator? The reporting attributes are already configured in the end device and have tested the same in third party coordinators such as deconz.
    2. If bind request from coordinator is mandatory, can you point me to any resources, possibly some sample codes which can help me to do the same.
    3. If local binding on the end device is possible, any help regarding how it can be done.
we are using nrf Connect SDK V2.1.0, on nrf52840
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