adb not starting: ADB_VENDOR_KEYS

Hi,

I am trying to launch adb but get:

daemon not running. starting it now on port 5037 *

daemon started successfully * error: device unauthorized. This adbd's $ADB_VENDOR_KEYS is not set; try 'adb kill-server' if that seems wrong. Otherwise check for a confirmation dialog on your device.

Tried every suggestion on other posts and none of them have worked

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